SIOS SANless clusters | Page 2 of 126 | SIOS SANless clusters High-availability Machine Learning monitoring

August 30, 2020	What If We Eliminated Apache Downtime? *Eliminate Apache web server downtime with SIOS AppKeeper Monitoring Today Apache webservers are the most popular webservers on the Internet. Companies are deploying mission-critical, customer-facing applications built on Apache using cloud platforms such as Amazon AWS, Microsoft Azure, and Google Cloud Platform. So you can bet that they are investing a lot of time and money in monitoring those applications and trying to reduce downtime. But what if we told you we could eliminate the need for manual intervention via automated monitoring and restarting applications when your Apache web servers are down? Before we go into how we can do that, let’s step back for a minute and look at choices that companies have when it comes to monitoring and managing their Apache web servers and those critical applications. How to monitor and protect your Apache web servers from unnecessary downtime Anyone deploying applications using Apache webservers is either considering monitoring the health of their webservers themselves or outsourcing that task to a third party. When it comes to monitoring cloud applications running on Amazon Web Services, a popular choice is to use Amazon CloudWatch. Some companies are even extending the functionality of CloudWatch by creating some levels of automation by developing scripts or by using AWS Lambda. But configuring Amazon CloudWatch properly with custom metrics and setting up AWS Lambda requires a certain amount of technical expertise that may be beyond that of many companies. And then there is a cost and effort required to maintain any scripts as the applications evolve. Another choice is to invest in a comprehensive Application Performance Monitoring (“APM”) solution from a vendor such as New Relics, Dynatrace, DataDog, or LogicMonitor. These can be very appropriate if you want to monitor more than just your AWS environment. APM solutions are very configurable and will provide you with a lot of data in terms of information about what happened. But have you reduced your downtime? Probably not. What you have done is invested in a system that will alert you immediately if and when your Apache webservers go down, and will overload you with data (or “alert storms”) as you try to get things running again. Some companies have decided to outsource the responsibility for monitoring and managing their applications to a trusted third party (often a “managed service provider” or MSP). In return for a base monthly fee, the MSP monitors applications and offers a core set of services, often bound by a Service Level Agreement. When alerts are received, they investigate. In some cases, these investigations can require (costly) escalations. If and when applications go down, the MSP will then take control and restart services or reboot instances where they can. But these remediation actions are often an extra expense. There has to be a better way. How automated monitoring and restart with SIOS AppKeeper eliminates Apache Webserver downtime** Based on our customer experience, the average company with only three EC2 instances experiences downtime at least once a month. “The site is down! Drop everything. Find out what needs to be done!” What you need to do is reduce the need for these unnecessary fire drills. SIOS AppKeeper is a SaaS service that is easy to install and configure and monitors any services and applications running on Amazon EC2, such as your Apache httpd service. When an anomaly is detected, AppKeeper automatically restarts the service, and if that doesn’t work it reboots the entire instance. No more reading through logs to pinpoint the reason for the failure, or escalation to developers to restart your service. Or expensive outsourcing fees. AppKeeper provides “set-it-and-forget-it” functionality so that you can eliminate downtime. Today hundreds of companies rely on AppKeeper to keep their cloud environments running. We invite you to check out the video below for a demonstration of how AppKeeper protects Apache webservers. And if you like what you see, please feel free to sign up for a free 14-day trial of AppKeeper. Based on customer data, AppKeeper addresses 85% of application service failures. So in almost nine times out of ten* AppKeeper sends out an email notifying customers that downtime was detected and the services were restarted or the instances were rebooted automatically. Isn’t that better than panicking and digging through log files before manually restarting everything? See related post: Why is AWS EC2 Application Monitoring So Hard? Reproduced with permission from SIOS
August 25, 2020	Tips for Restoring SIOS Protection Suite for Linux Configuration Specifics Tips for Restoring SIOS Protection Suite for Linux Configuration Specifics Nice job “Random Co-worker”! And by nice job, I didn’t really mean nice job. And by “Random Coworker” I mean the guy who checked the box that shouldn’t be checked, or unchecked the box that should be checked, the man or woman who skipped the message and the warning, and the “Please confirm” safety measures and just wrecked your SIOS Protection Suite for Linux configuration. We’ve all been there. It was an accident. However it happened, it happened. Suddenly you are scrambling to figure out what to do to recover the configuration, the data, and the “whatever” before the boss finds out. As the VP of Customer Experience at SIOS Technology Corp. our teams are actively working with partners and customers to architect and implement enterprise availability to protect their systems from downtime. Accidents happen, and a recent customer experience reminded me that even with our multiple checks and warnings, even the SIOS Protection Suite for Linux product isn’t immune to accidental configuration changes, but there is a simple tip for faster recovery from the “Random Coworker’s” accidental blunder. How to Recover SIOS Protection Suite for Linux After Accidental Configuration Changes Native to the SIOS Protection Suite for Linux (SPS-L) is a tool called lkbackup, located under /opt/LifeKeeper/bin/lkbackup. The tool, as the name might suggest, creates a backup of the SPS-L configuration details. Note: This tool does not backup all of the application data, but it does create a backup of all the data for the SPS-L configuration such as: resource definitions, tunables configured in the /etc/default/LifeKeeper file, customer created generic application scripts, flags associated with the state of the cluster, communication path/cluster definitions, and more. [root@baymax ~ ] # /opt/LifeKeeper/bin/lkbackup -c -f /root/mylkbackup-5.15.2020-v9.4.1 –cluster –ssh Example: : lkbackup create syntax This creates a backup file named mylkbackup-5.15.2020-v9.4.1 under the /root folder. The –cluster tells lkbackup to create the same file on each cluster node. The –ssh uses ssh protocol to connect to each cluster node. Additional lkbackup details are here: Our Customer Experience Services Team recommends taking a backup before making SPS-L configuration changes, such as upgrades, resource removal or addition, or configuration changes. So when you need to restore the SPS-L configuration, the change is as simple as running lkbackup again. [root@baymax ~ ] # /opt/LifeKeeper/bin/lkbackup -x -f /root/mylkbackup-5.15.2020-v9.4.1 –cluster –ssh Example: lkbackup restore syntax Autobackup Feature Automatically Captures a lkbackup File But, what do you do if you forgot to run lkbackup to create this file before your “Random Coworker” blundered away hours of SPS-L setup and configuration? What do you do if the “Guy” or “Gal” who set up SPS-L is on vacation, paternity or maternity leave? What if you are the “Random Coworker” and Steve from the Basis Team is heading down the hallway to see how things are going? For most installations, SIOS enables an autobackup feature during the installation. This autobackup feature will automatically capture a lkbackup file for you at 3am local time, under /opt/LifeKeeper/config/auto-backup.#.tgz [root@baymax ~]# ls -ltr /opt/LifeKeeper/config/auto-backup.* -rw-r–r–. 1 root root 31312 May 6 03:00 /opt/LifeKeeper/config/auto-backup.3.tgz -rw-r–r–. 1 root root 31310 May 7 03:00 /opt/LifeKeeper/config/auto-backup.4.tgz -rw-r–r–. 1 root root 31284 May 8 03:00 /opt/LifeKeeper/config/auto-backup.5.tgz -rw-r–r–. 1 root root 31290 May 9 03:00 /opt/LifeKeeper/config/auto-backup.6.tgz -rw-r–r–. 1 root root 31291 May 10 03:00 /opt/LifeKeeper/config/auto-backup.7.tgz -rw-r–r–. 1 root root 31295 May 11 03:00 /opt/LifeKeeper/config/auto-backup.8.tgz -rw-r–r–. 1 root root 31280 May 12 03:00 /opt/LifeKeeper/config/auto-backup.9.tgz -rw-r–r–. 1 root root 31333 May 13 03:00 /opt/LifeKeeper/config/auto-backup.0.tgz -rw-r–r–. 1 root root 31325 May 14 03:00 /opt/LifeKeeper/config/auto-backup.1.tgz -rw-r–r–. 1 root root 31359 May 15 03:00 /opt/LifeKeeper/config/auto-backup.2.tgz Example. Output from config/auto-backup listing If your system has been installed and configured properly, the autobackups have been running each night, ready to cover you when your “Random Coworker” strikes. Find the SPS-L auto-backup.#.tgz before the blunder, and using the SPS-L lkbackup tool, retrieve and restore your SIOS Protection Suite for Linux Configuration to the previously configured state. [root@baymax ~ ] # lkstop; /opt/LifeKeeper/bin/lkbackup -c -f /opt/LifeKeeper/config/auto-backup.0.tgz Example: lkbackup restore syntax for auto-backup Repeat this on the other nodes in the cluster as required. Note. If your system doesn’t appear to be configured to generate the auto-backup files and protect you from your own “Random Coworker”, SIOS offers installation and configuration services, and configuration health checks performed by a SIOS Professional Services Engineer. — Cassius Rhue, VP, Customer Experience Reproduced with permission from SIOS
August 18, 2020	Step-By-Step: How to configure a SANless MySQL Linux failover cluster in Amazon EC2 Step-By-Step: How to configure a SANless MySQL Linux failover cluster in Amazon EC2 In this step by step guide, I will take you through all steps required to configure a highly available, 2-node MySQL cluster (plus witness server) in Amazon’s Elastic Compute Cloud (Amazon EC2). The guide includes both screenshots, shell commands and code snippets as appropriate. I assume that you are somewhat familiar with Amazon EC2 and already have an account. If not, you can sign up today. I’m also going to assume that you have basic familiarity with Linux system administration and failover clustering concepts like Virtual IPs, etc. Failover clustering has been around for many years. In a typical configuration, two or more nodes are configured with shared storage to ensure that in the event of a failover on the primary node, the secondary or target node(s) will access the most up-to-date data. Using shared storage not only enables a near-zero recovery point objective, it is a mandatory requirement for most clustering software. However, shared storage presents several challenges. First, it is a single point of failure risk. If shared storage – typically a SAN – fails, all nodes in the cluster fails. Second, SANs can be expensive and complex to purchase, setup and manage. Third, shared storage in public clouds, including Amazon EC2 is either not possible, or not practical for companies that want to maintain high availability (99.99% uptime), near-zero recovery time and recovery point objectives, and disaster recovery protection. The following demonstrates how easy it is to create a SANless cluster in the clouds to eliminate these challenges while meeting stringent HA/DR SLAs. The steps below use MySQL database with Amazon EC2 but the same steps could be adapted to create a 2-node cluster in AWS to protect SQL, SAP, Oracle, or any other application. NOTE: Your view of features, screens and buttons may vary slightly from screenshots presented below 1. Create a Virtual Private Cloud (VPC) 2. Create an Internet Gateway 3. Create Subnets (Availability Zones) 4. Configure Route Tables 5. Configure Security Group 6. Launch Instances 7. Create Elastic IP 8. Create Route Entry for the Virtual IP 9. Disable Source/Dest Checking for ENIs 10. Obtain Access Key ID and Secret Access Key 11. Linux OS Configuration 12. Install EC2 API Tools 13. Install and Configure MySQL 14. Install and Configure Cluster 15. Test Cluster Connectivity Overview This article will describe how to create a cluster within a single Amazon EC2 region. The cluster nodes (node1, node2 and the witness server) will reside different Availability Zones for maximum availability. This also means that the nodes will reside in different subnets. The following IP addresses will be used: node1: 10.0.0.4 node2: 10.0.1.4 witness: 10.0.2.4 virtual/”floating” IP: 10.1.0.10 Step 1: Create a Virtual Private Cloud (VPC) First, create a Virtual Private Cloud (aka VPC). A VPC is an isolated network within the Amazon cloud that is dedicated to you. You have full control over things like IP address blocks and subnets, route tables, security groups (i.e. firewalls), and more. You will be launching your Azure Iaas virtual machines (VMs) into your Virtual Network. From the main AWS dashboard, select “VPC” Under “Your VPCs”, make sure you have selected the proper region at the top right of the screen. In this guide the “US West (Oregon)” region will be used, because it is a region that has 3 Availability Zones. For more information on Regions and Availability Zones, click here. Give the VPC a name, and specify the IP block you wish to use. 10.0.0.0/16 will be used in this guide: You should now see the newly created VPC on the “Your VPCs” screen: Step 2: Create an Internet Gateway Next, create an Internet Gateway. This is required if you want your Instances (VMs) to be able to communicate with the internet. On the left menu, select Internet Gateways and click the Create Internet Gateway button. Give it a name, and create: Next, attach the internet gateway to your VPC: Select your VPC, and click Attach: Step 3: Create Subnets (Availability Zones) Next, create 3 subnets. Each subnet will reside in it’s own Availability Zone. The 3 Instances (VMs: node1, node2, witness) will be launched into separate subnets (and therefore Availability Zones) so that the failure of an Availability Zone won’t take out multiple nodes of the cluster. The US West (Oregon) region, aka us-west-2, has 3 availability zones (us-west-2a, us-west-2b, us-west-2c). Create 3 subnets, one in each of the 3 availability zones. Under VPC Dashboard, navigate to Subnets, and then Create Subnet: Give the first subnet a name (“Subnet1)”, select the availability zone us-west-2a, and define the network block (10.0.0.0/24): Repeat to create the second subnet availability zone us-west-2b: Repeat to create the third subnet in availability zone us-west-2c: Once complete, verify that the 3 subnets have been created, each with a different CIDR block, and in separate Availability Zones, as seen below: Step 4: Configure Route Tables Update the VPC’s route table so that traffic to the outside world is sent to the Internet Gateway created in a previous step. From the VPC Dashboard, select Route Tables. Go to the Routes tab, and by default only one route will exist which allows traffic only within the VPC. Click Edit: Add another route: The Destination of the new route will be “0.0.0.0/0” (the internet) and for Target, select your Internet Gateway. Then click Save: Next, associate the 3 subnets with the Route Table. Click the “Subnet Associations” tab, and Edit: Check the boxes next to all 3 subnets, and Save: Verify that the 3 subnets are associated with the main route table: Later, we will come back and update the Route Table once more, defining a route that will allow traffic to communicate with the cluster’s Virtual IP, but this needs to be done AFTER the linux Instances (VMs) have been created. Step 5: Configure Security Group Edit the Security Group (a virtual firewall) to allow incoming SSH and VNC traffic. Both will later be used to configure the linux instances as well as installation/configuration of the cluster software. On the left menu, select “Security Groups” and then click the “Inbound Rules” tab. Click Edit: Add rules for both SSH (port 22) and VNC. VNC generally uses ports in the 5900, depending on how you configure it, so for the purposes of this guide, we will open the 5900-5910 port range. Configure accordingly based on your VNC setup: Step 6: Launch Instances We will be provisioning 3 Instances (Virtual Machines) in this guide. The first two VMs (called “node1” and “node2”) will function as cluster nodes with the ability to bring the MySQL database and it’s associated resources online. The 3rd VM will act as the cluster’s witness server for added protection against split-brain. To ensure maximum availability, all 3 VMs will be deployed into different Availability Zones within a single region. This means each instance will reside in a different subnet. Go to the main AWS dashboard, and select EC2: Create “node1” Create your first instance (“node1”). Click Launch Instance: Select your linux distribution. The cluster software used later supports RHEL, SLES, CentOS and Oracle Linux. In this guide we will be using RHEL 7.X: Size your instance accordingly. For the purposes of this guide and to minimize cost, t2.micro size was used because it’s free tier eligible. See here for more information on instance sizes and pricing. Next, configure instance details. IMPORTANT: make sure to launch this first instance (VM) into “Subnet1“, and define an IP address valid for the subnet (10.0.0.0/24) – below 10.0.0.4 is selected because it’s the first free IP in the subnet. NOTE: .1/.2/.3 in any given subnet in AWS is reserved and can’t be used. Next, add an extra disk to the cluster nodes (this will be done on both “node1” and “node2”). This disk will store our MySQL databases and the later be replicated between nodes. NOTE: You do NOT need to add an extra disk to the “witness” node. Only “node1” and “node2”. Add New Volume, and enter in the desired size: Define a Tag for the instance, Node1: Associate the instance with the existing security group, so the firewall rules created previous will be active: Click Launch: IMPORTANT: If this is the first instance in your AWS environment, you’ll need to create a new key pair. The private key file will need to be stored in a safe location as it will be required when you SSH into the linux instances. Create “node2” Repeat the steps above to create your second linux instance (node2). Configure it exactly like Node1. However, make sure that you deploy it into “Subnet2” (us-west-2b availability zone). The IP range for Subnet2 is 10.0.1.0/24, so an IP of 10.0.1.4 is used here: Make sure to add a 2nd disk to Node2 as well. It should be the same exact size as the disk you added to Node1: Give the second instance a tag…. “Node2”: Create “witness” Repeat the steps above to create your third linux instance (witness). Configure it exactly like Node1&Node2, EXCEPT you DON’T need to add a 2nd disk, since this instance will only act as a witness to the cluster, and won’t ever bring MySQL online. Make sure that you deploy it into “Subnet3” (us-west-2c availability zone). The IP range for Subnet2 is 10.0.2.0/24, so an IP of 10.0.2.4 is used here: NOTE: default disk configuration is fine for the witness node. A 2nd disk is NOT required: Tag the witness node: It may take a little while for your 3 instances to provision. Once complete, you’ll see then listed as running in your EC2 console: Step 7: Create Elastic IP Next, create an Elastic IP, which is a public IP address that will be used to connect into you instance from the outside world. Select Elastic IPs in the left menu, and then click “Allocate New Address”: Select the newly created Elastic IP, right-click, and select “Associate Address”: Associate this Elastic IP with Node1: Repeat this for the other two instances if you want them to have internet access or be able to SSH/VNC into them directly. Step 8: create Route Entry for the Virtual IP At this point all 3 instances have been created, and the route table will need to be updated one more time in order for the cluster’s Virtual IP to work. In this multi-subnet cluster configuration, the Virtual IP needs to live outside the range of the CIDR allocated to your VPC. Define a new route that will direct traffic to the cluster’s Virtual IP (10.1.0.10) to the primary cluster node (Node1) From the VPC Dashboard, select Route Tables, click Edit. Add a route for “10.1.0.10/32” with a destination of Node1: Step 9: Disable Source/Dest Checking for ENIs Next, disable Source/Dest Checking for the Elastic Network Interfaces (ENI) of your cluster nodes. This is required in order for the instances to accept network packets for the virtual IP address of the cluster. Do this for all ENIs. Select “Network Interfaces”, right-click on an ENI, and select “Change Source/Dest Check”. Select “Disabled“: Step 10: Obtain Access Key ID and Secret Access Key Later in the guide, the cluster software will use the AWS Command Line Interface (CLI) to manipulate a route table entry for the cluster’s Virtual IP to redirect traffic to the active cluster node. In order for this to work, you will need to obtain an Access Key ID and Secret Access Key so that the AWS CLI can authenticate properly. In the top-right of the EC2 Dashboard, click on your name, and underneath select “Security Credentials” from the drop-down: Expand the “Access Keys (Access Key ID and Secret Access Key)” section of the table, and click “Create New Access Key”. Download Key File and store the file in a safe location. Step 11: Configure Linux OS Connect to the linux instance(s): To connect to your newly created linux instances (via SSH), right-click on the instance and select “Connect”. This will display the instructions for connecting to the instance. You will need the Private Key File you created/downloaded in a previous step: Example: Here is where we will leave the EC2 Dashboard for a little while and get our hands dirty on the command line, which as a Linux administrator you should be used to by now. You aren’t given the root password to your Linux VMs in AWS (or the default “ec2-user” account either), so once you connect, use the “sudo” command to gain root privileges: $sudo su – Unless you have already have a DNS server setup, you’ll want to create host file entries on all 3 servers so that they can properly resolve each other by nameEdit /etc/hosts Add the following lines to the end of your /etc/hosts file: 10.0.0.4 node1 10.0.1.4 node2 10.0.2.4 witness 10.1.0.10 mysql-vip Disable SELinux Edit /etc/sysconfig/linux and set “SELINUX=disabled”: # vi /etc/sysconfig/selinux # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing – SELinux security policy is enforced. # permissive – SELinux prints warnings instead of enforcing. # disabled – No SELinux policy is loaded. SELINUX=disabled # SELINUXTYPE= can take one of these two values: # targeted – Targeted processes are protected, # mls – Multi Level Security protection. SELINUXTYPE=targeted Set Hostnames By default, these Linux instances will have a hostname that is based upon the server’s IP address, something like “ip-10-0-0-4.us-west-2.compute.internal” You might notice that if you attempt to modify the hostname the “normal” way (i.e. editing /etc/sysconfig/network, etc), after each reboot, it reverts back to the original!! I found a great thread in the AWS discussion forums that describes how to actually get hostnames to remain static after reboots. Details here: https://forums.aws.amazon.com/message.jspa?messageID=560446 Comment out modules that set hostname in “/etc/cloud/cloud.cfg” file. The following modules can be commented out using #. # – set_hostname # – update_hostname Next, also change your hostname in /etc/hostname. Reboot Cluster Nodes Reboot all 3 instances so that SELinux is disabled, and the hostname changes take effect. Install and Configure VNC (and related packages) In order to access the GUI of our linux servers, and to later install and configure our cluster, install VNC server, as well as a handful of other required packages (cluster software needs the redhat-lsb and patch rpms). # yum groupinstall “X Window System” # yum groupinstall “Server with GUI” # yum install tigervnc-server xterm wget unzip patch redhat-lsb # vncpasswd The following URL is a great guide to getting VNC Server running on RHEL 7 / CentOS 7:For RHEL 7.x/CentOS7.x: https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-vnc-remote-access-for-the- gnome-desktop-on-centos-7 NOTE: This example configuration runs VNC on display 2 (:2, aka port 5902) and as root (not secure). Adjust accordingly! # cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:2.serv # vi /etc/systemd/system/vncserver@:2.service [Service] Type=forking # Clean any existing files in /tmp/.X11-unix environment ExecStartPre=/bin/sh -c ‘/usr/bin/vncserver -kill %i > /dev/null 2>&1 \|\| :’ ExecStart=/sbin/runuser -l root -c “/usr/bin/vncserver %i -geometry 1024×768” PIDFile=/root/.vnc/%H%i.pid ExecStop=/bin/sh -c ‘/usr/bin/vncserver -kill %i > /dev/null 2>&1 \|\| :’ # systemctl daemon-reload # systemctl enable vncserver@:2.service # vncserver :2 -geometry 1024×768 For RHEL/CentOS 6.x systems: # vi /etc/sysconfig/vncservers VNCSERVERS=”2:root” VNCSERVERARGS[2]=”-geometry 1024×768″ # service vncserver start # chkconfig vncserver on Open a VNC client, and connect to the <ElasticIP:2>. If you can’t get it, it’s likely your linux firewall is in the way. Either open the VNC port we are using here (port 5902), or for now, disable the firewall (NOT RECOMMENDED FOR PRODUCTION ENVIRONMENTS): # systemctl stop firewalld # systemctl disable firewalld Partition and Format the “data” disk When the linux instances were launched, and extra disk was added to each cluster node to store the application data we will be protecting. In this case it happens to be MySQL databases. The second disk should appear as /dev/xvdb. You can run the “fdisk -l” command to verify. You’ll see that /dev/xvda (OS) is already being used. # fdisk -l # Start End Size Type NameDisk /dev/xvda: 10.7 GB, 10737418240 bytes, 20971520 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: gpt 1 2048 4095 1M BIOS boot parti 2 4096 20971486 10G Microsoft basic Disk /dev/xvdb: 2147 MB, 2147483648 bytes, 4194304 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Here I will create a partition (/dev/xvdb1), format it, and mount it at the default location for MySQL, which is /var/lib/mysql. Perform the following steps on BOTH “node1” and “node2”: # fdisk /dev/xvdb Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Device does not contain a recognized partition table Building a new DOS disklabel with disk identifier 0x8c16903a. Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): p Partition number (1-4, default 1): 1 First sector (2048-4194303, default 2048): <enter> Using default value 2048 Last sector, +sectors or +size{K,M,G} (2048-4194303, default 4194303): <enter> Using default value 4194303 Partition 1 of type Linux and of size 2 GiB is set Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks. # mkfs.ext4 /dev/xvdb1 # mkdir /var/lib/mysql On node1, mount the filesystem: # mount /dev/xvdb1 /var/lib/mysql The EC2 API Tools (EC2 CLI) must be installed on each of the cluster nodes, so that the cluster software can later manipulate Route Tables, enabling connectivity to the Virtual IP. Step 12: Install EC2 API Tools The following URL is an excellent guide to setting this up: http://docs.aws.amazon.com/AWSEC2/latest/CommandLineReference/set-up-ec2-cli-linux.html Here are the key steps: Download, unzip, and move the CLI tools to the standard location (/opt/aws): # wget http://s3.amazonaws.com/ec2-downloads/ec2-api-tools.zip # unzip ec2-api-tools.zip # mv ec2-api-tools-1.7.5.1/ /opt/aws/ # export EC2_HOME=”/opt/aws” If java isn’t already installed (run “which java” to check), install it: # yum install java-1.8.0-openjdk # export JAVA_HOME=”/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.71- Example (Based on default config of RHEL 7.2 system. Adjust accordingly) You’ll need your AWS Access Key and AWS Secret Key. Keep these values handy, because they will be needed later during cluster setup too! Refer to the following URL for more information: https://console.aws.amazon.com/iam/home?#security_credential # export AWS_ACCESS_KEY=your-aws-access-key-id # export AWS_SECRET_KEY=your-aws-secret-key Test CLI utility functionality: # /opt/aws/bin/ec2-describe-regions REGION eu-west-1 ec2.eu-west-1.amazonaws.com REGION ap-southeast-1 ec2.ap-southeast-1.amazonaws.com REGION ap-southeast-2 ec2.ap-southeast-2.amazonaws.com REGION eu-central-1 ec2.eu-central-1.amazonaws.com REGION ap-northeast-2 ec2.ap-northeast-2.amazonaws.com REGION ap-northeast-1 ec2.ap-northeast-1.amazonaws.com REGION us-east-1 ec2.us-east-1.amazonaws.com REGION sa-east-1 ec2.sa-east-1.amazonaws.com REGION us-west-1 ec2.us-west-1.amazonaws.com REGION us-west-2 ec2.us-west-2.amazonaws.com Step 13: Install and Configure MySQL Next, install the MySQL packages, initialize a sample database, and set “root” password for MySQL. In RHEL7.X, the MySQL packages have been replaced with the MariaDB packages. On “node1”: # yum install mariadb mariadb-server # mount /dev/xvdb1 /var/lib/mysql # /usr/bin/mysql_install_db –datadir=”/var/lib/mysql/” –user=mysql # mysqld_safe –user=root –socket=/var/lib/mysql/mysql.sock –port=3306 –datadi # # # NOTE: This next command allows remote connections from ANY host. NOT a good # echo “update user set Host=’%’ where Host=’node1′; flush privileges \| mysql mys # # #Set MySQL’s root password to ‘SIOS’ # echo “update user set Password=PASSWORD(‘SIOS’) where User=’root’; flush Create a MySQL configuration file. We will place this on the data disk (that will later be replicated – /var/lib/mysql/my.cnf). Example: # vi /var/lib/mysql/my.cnf [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock pid-file=/var/run/mariadb/mariadb.pid user=root port=3306 # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 [mysqld_safe] log-error=/var/log/mariadb/mariadb.log pid-file=/var/run/mariadb/mariadb.pid [client] user=root password=SIOS Move the original MySQL configuration file aside, if it exists: # mv /etc/my.cnf /etc/my.cnf.orig On “node2”, you ONLY need to install the MariaDB/MySQL packages. The other steps aren’t required:On “node2”: [root@node2 ~]# yum install mariadb mariadb-server Step 14: Install and Configure the Cluster At this point, we are ready to install and configure our cluster. SIOS Protection Suite for Linux (aka SPS-Linux) will be used in this guide as the clustering technology. It provides both high availability failover clustering features (LifeKeeper) as well as real-time, block level data replication (DataKeeper) in a single, integrated solution. SPS-Linux enables you to deploy a “SANLess” cluster, aka a “shared nothing” cluster meaning that cluster nodes don’t have any shared storage, as is the case with EC2 Instances. Install SIOS Protection Suite for Linux Perform the following steps on ALL 3 VMs (node1, node2, witness): Download the SPS-Linux installation image file (sps.img) and and obtain either a trial license or purchase permanent licenses. Contact SIOS for more information. You will loopback mount it and run the “setup” script inside, as root (or first “sudo su -” to obtain a root shell) For example: # mkdir /tmp/install # mount -o loop sps.img /tmp/install # cd /tmp/install # ./setup During the installation script, you’ll be prompted to answer a number of questions. You will hit Enter on almost every screen to accept the default values. Note the following exceptions: On the screen titled “High Availability NFS” you may select “n” as we will not be creating a highly available NFS server Towards the end of the setup script, you can choose to install a trial license key now, or later. We will install the license key later, so you can safely select “n” at this point In the final screen of the “setup” select the ARKs (Application Recovery Kits, i.e. “cluster agents”) you wish to install from the list displayed on the screen. The ARKs are ONLY required on “node1” and “node2”. You do not need to install on “witness” Navigate the list with the up/down arrows, and press SPACEBAR to select the following: lkDR – DataKeeper for Linux lkSQL – LifeKeeper MySQL RDBMS Recovery Kit This will result in the following additional RPMs installed on “node1” and “node2”: steeleye-lkDR-9.0.2-6513.noarch.rpm steeleye-lkSQL-9.0.2-6513.noarch.rpm Install Witness/Quorum package The Quorum/Witness Server Support Package for LifeKeeper (steeleye-lkQWK) combined with the existing failover process of the LifeKeeper core allows system failover to occur with a greater degree of confidence in situations where total network failure could be common. This effectively means that failovers can be done while greatly reducing the risk of “split-brain” situations. Install the Witness/Quorum rpm on all 3 nodes (node1, node2, witness): # cd /tmp/install/quorum # rpm -Uvh steeleye-lkQWK-9.0.2-6513.noarch.rpm On ALL 3 nodes (node1, node2, witness), edit /etc/default/LifeKeeper, set NOBCASTPING=1 On ONLY the Witness server (“witness”), edit /etc/default/LifeKeeper, set WITNESS_MODE=off/none Install the EC2 Recovery Kit Package SPS-Linux provides specific features that allow resources to failover between nodes in different availability zones and regions. Here, the EC2 Recovery Kit (i.e. cluster agent) is used to manipulate Route Tables so that connections to the Virtual IP are routed to the active cluster node. Install the EC2 rpm (node1, node2): # cd /tmp/install/amazon # rpm -Uvh steeleye-lkECC-9.0.2-6513.noarch.rpm Install a License key On all 3 nodes, use the “lkkeyins” command to install the license file that you obtained from SIOS: # /opt/LifeKeeper/bin/lkkeyins <path_to_file>/<filename>.lic Start LifeKeeper On all 3 nodes, use the “lkstart” command to start the cluster software: # /opt/LifeKeeper/bin/lkstart Set User Permissions for LifeKeeper GUI On all 3 nodes, create a new linux user account (i.e. “tony” in this example). Edit /etc/group and add the “tony” user to the “lkadmin” group to grant access to the LifeKeeper GUI. By default only “root” is a member of the group, and we don’t have the root password here: # useradd tony # passwd tony # vi /etc/group lkadmin:x:1001:root,tony Open the LifeKeeper GUI Make a VNC connection to the Elastic IP (Public IP) address of node1. Based on the VNC configuration from above, you would connect to <Public_IP>:2 using the VNC password you specified earlier. Once logged in, open a terminal window and run the LifeKeeper GUI using the following command: # /opt/LifeKeeper/bin/lkGUIapp & You will be prompted to connect to your first cluster node (“node1”). Enter the linux userid and password specified during VM creation: Next, connect to both “node2” and “witness” by clicking the “Connect to Server” button highlighted in the following screenshot: You should now see all 3 servers in the GUI, with a green checkmark icon indicating they are online and healthy: Create Communication Paths Right-click on “node1” and select Create Comm Path Select BOTH “node2” and “witness” and then follow the wizard. This will create comm paths between: node1 & node2 node1 & witness A comm path still needs to be created between node2 & witness. Right click on “node2” and select Create Comm Path. Follow the wizard and select “witness” as the remote server: At this point the following comm paths have been created: node1 <—> node2 node1 <—> witness node2 <—> witness The icons in front of the servers have changed from a green “checkmark” to a yellow “hazard sign”. This is because we only have a single communication path between nodes. If the VMs had multiple NICs (information on creating Azure VMs with multiple NICs can be found here, but won’t be covered in this article), you would create redundant comm paths between each server. To remove the warning icons, go to the View menu and de-select “Comm Path Redundancy Warning”: Result: Verify Communication Paths Use the “lcdstatus” command to view the state of cluster resources. Run the following commands to verify that you have correctly created comm paths on each node to the other two servers involved: # /opt/LifeKeeper/bin/lcdstatus -q -d node1 MACHINE NETWORK ADDRESSES/DEVICE STATE PRIO node2 TCP 10.0.0.4/10.0.1.4 ALIVE 1 witness TCP 10.0.0.4/10.0.2.4 ALIVE 1 #/opt/LifeKeeper/bin/lcdstatus -q -d node2 MACHINE NETWORK ADDRESSES/DEVICE STATE PRIO node1 TCP 10.0.1.4/10.0.0.4 ALIVE 1 witness TCP 10.0.1.4/10.0.2.4 ALIVE 1 #/opt/LifeKeeper/bin/lcdstatus -q -d witness MACHINE NETWORK ADDRESSES/DEVICE STATE PRIO node1 TCP 10.0.2.4/10.0.0.4 ALIVE 1 node2 TCP 10.0.2.4/10.0.1.4 ALIVE 1 Create a Data Replication cluster resource (i.e. Mirror) Next, create a Data Replication resource to replicate the /var/lib/mysql partition from node1 (source) to node2 (target). Click the “green plus” icon to create a new resource: Follow the wizard with these selections: Please Select Recovery Kit: Data Replication Switchback Type: intelligent Server: node1 Hierarchy Type: Replicate Exiting Filesystem Existing Mount Point: /var/lib/mysql Data Replication Resource Tag: datarep-mysql File System Resource Tab: /var/lib/mysql Bitmap File: (default value) Enable Asynchronous Replication: No After the resource has been created, the “Extend” (i.e. define backup server) wizard will appear. Use the following selections: Target Server: node2 Switchback Type: Intelligent Template Priority: 1 Target Priority: 10 Target Disk: /dev/xvdb1 Data Replication Resource Tag: datarep-mysql Bitmap File: (default value) Replication Path: 10.0.0.4/10.0.1.4 Mount Point: /var/lib/mysql Root Tag: /var/lib/mysql The cluster will look like this: Create Virtual IP Next, create a Virtual IP cluster resource. Click the “green plus” icon to create a new resource: Follow the wizard to create the IP resource with these selections: Select Recovery Kit: IP Switchback Type: Intelligent IP Resource: 10.1.0.10 Netmask: 255.255.255.0 Network Interface: eth0 IP Resource Tag: ip-10.1.0.10 Extend the IP resource with these selections: Switchback Type: Intelligent Template Priority: 1 Target Priority: 10 IP Resource: 10.1.0.10 Netmask: 255.255.255.0 Network Interface: eth0 IP Resource Tag: ip-10.1.0.10 The cluster will now look like this, with both Mirror and IP resources created: Configure a Ping List for the IP resource By default, SPS-Linux monitors the health of IP resources by performing a broadcast ping. In many virtual and cloud environments, broadcast pings don’t work. In a previous step, we set “NOBCASTPING=1” in /etc/default/LifeKeeper to turn off broadcast ping checks. Instead, we will define a ping list. This is a list of IP addresses to be pinged during IP health checks for this IP resource. In this guide, we will add the witness server (10.0.2.4) to our ping list. Right-click on the IP resource (ip-10.1.0.10) and select Properties: You will see that initially, no ping list is configured for our 10.1.0.0 subnet. Click “Modify Ping List”: Enter “10.0.2.4” (the IP address of our witness server), click “Add address” and finally click “Save List”: You will be returned to the IP properties panel, and can verify that 10.0.2.4 has been added to the ping list. Click OK to close the window: Create the MySQL resource hierarchy Next, create a MySQL cluster resource. The MySQL resource is responsible for stopping/starting/monitoring of your MySQL database. Before creating MySQL resource, make sure the database is running. Run “ps -ef \| grep sql” to check. If it’s running, great – nothing to do. If not, start the database back up: # mysqld_safe –user=root –socket=/var/lib/mysql/mysql.sock –port=3306 –datadi Follow the wizard with to create the IP resource with these selections:To create, click the “green plus” icon to create a new resource: Select Recovery Kit: MySQL Database Switchback Type: Intelligent Server: node1 Location of my.cnf: /var/lib/mysql Location of MySQL executables: /usr/bin Database Tag: mysql Extend the IP resource with the following selections: Target Server: node2 Switchback Type: intelligent Template Priority: 1 Target Priority: 10 As a result, your cluster will look as follows. Notice that the Data Replication resource was automatically moved underneath the database (dependency automatically created) to ensure it’s always brought online before the database: Create an EC2 resource to manage the route tables upon failover SPS-Linux provides specific features that allow resources to failover between nodes in different availability zones and regions. Here, the EC2 Recovery Kit (i.e. cluster agent) is used to manipulate Route Tables so that connections to the Virtual IP are routed to the active cluster node. To create, click the “green plus” icon to create a new resource: Follow the wizard to create the EC2 resource with these selections: Select Recovery Kit: Amazon EC2 Switchback Type: Intelligent Server: node1 EC2 Home: /opt/aws EC2 URL: ec2.us-west-2.amazonaws.com AWS Access Key: (enter Access Key obtained earlier) AWS Secret Key: (enter Secret Key obtained earlier) EC2 Resource Type: RouteTable (Backend cluster) IP Resource: ip-10.1.0.10 EC2 Resource Tag: ec2-10.1.0.10 Extend the IP resource with the following selections: Target Server: node2 Switchback Type: intelligent Template Priority: 1 Target Priority: 10 EC2 Resource Tag: ec2-10.1.0.10 The cluster will look like this. Notice how the EC2 resource is underneath the IP resource: Create a Dependency between the IP resource and the MySQL Database resource Create a dependency between the IP resource and the MySQL Database resource so that they failover together as a group. Right click on the “mysql” resource and select “Create Dependency”: On the following screen, select the “ip-10.1.0.10” resource as the dependency. Click Next and continue through the wizard: At this point the SPS-Linux cluster configuration is complete. The resource hierarchy will look as follows: Step 15: Test Cluster Connectivity At this point, all of our Amazon EC2 and Cluster configurations are complete! Cluster resources are currently active on node1: Test connectivity to the cluster from the witness server (or another linux instance if you have one) SSH into the witness server, “sudo su -” to gain root access. Install the mysql client if needed: [root@witness ~]# yum -y install mysql Test MySQL connectivity to the cluster: [root@witness ~]# mysql –host=10.1.0.10 mysql -u root -p Execute the following MySQL query to display the hostname of the active cluster node: MariaDB [mysql]> select @@hostname; ++ \| @@hostname \| ++ \| node1 \| ++ 1 row in set (0.00 sec) MariaDB [mysql]> Using LifeKeeper GUI, failover from Node1 -> Node2″. Right-click on the mysql resource underneath node2, and select “In Service…”: After failover has completed, re-run the MySQL query. You’ll notice that the MySQL client has detected that the session was lost (during failover) and automatically reconnects: Execute the following MySQL query to display the hostname of the active cluster node, verifying that now “node2” is active: MariaDB [mysql]> select @@hostname; ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect… Connection id: 12 Current database: mysql ++ \| @@hostname \| ++ \| node2 \| ++ 1 row in set (0.53 sec) MariaDB [mysql]> Reproduced with permission from SIOS
August 11, 2020	Lessons in Cloud High Availability from the Movies Lessons in Cloud High Availability from the Movies Joseph Lalonde of jmlalonde.com has a blog highlighting the leadership lessons from popular movies such as Hancock, The Greatest Showman, and Frozen II. In credit to Joseph’s inspiring leadership lessons, here are four high availability lessons on cloud migration from Disney’s Frozen II. Disney’s Frozen II and Cloud Migration Lessons In Disney’s animated adventure Frozen II the characters Anna, Elsa, Kristoff, Olaf and Sven leave Arendelle to travel to an ancient, autumn-bound forest of an enchanted land. In the adventure, they set out to find the origin of Elsa’s powers in order to save their kingdom. Aside from being fun for a father of six girls, the movie is also ripe with leadership, life, and high availability lessons. 1. You can’t go into cloud migration without the proper help. When Elsa, Anna, Kristoff, Olaf and Sven arrive at the place where the mysterious voice has been calling them, they stand outside an enormous cloud. When Olaf and Kristoff attempt to enter, they are bounced back and repelled. It is only when Elsa approaches the cloud with her magic that the portal opens and they enter. When migrating to the cloud, there will be a lot of voices calling you. Some will beckon you to AWS, or Azure or GCP, or a myriad of others. But, no matter which you intend to go with, know that you will need the proper help for a successful entry. This help should include: Architects knowledgeable of the platform, especially the networking aspects Application administrators who understand the applications installation, configuration, operation and maintenance characteristics Security and OS administrators A cloud partner representative A knowledgeable availability expert for deploying critical applications in highly available architecture 2. Things will not make sense when you are older, so document and iterate. While walking through the enchanted forest, Olaf begins experiencing the strange phenomenon and magic of the forest. As he does, he begins to sing: This will all make sense when I am older Someday I will see that this makes sense One day, when I’m old and wise I’ll think back and realize That these were all completely normal events I’ll have all the answers when I’m older The song concludes with the rousing finish of: ‘Cause when you’re older Absolutely everything makes sense This is fine Stop. If things don’t make sense to you when you are starting out in your cloud journey, take the time to make them make sense. If you are using an agile mindset, launch an investigation spike on the singular topic or topics of confusion. For example, if you don’t understand the magic of the VPC, Security Group, Availability Zone or Set, Region, or Region to Region concepts today, they will make even less sense later down the road when you return to this configuration months later. If the test results don’t make sense, don’t move on, run them again. Also, remember to document the architecture, not just the details you think are important, but the details that the older you who have moved through six other projects and is facing a deadline would want to know to make it all make sense. 3. Don’t go running into the fire. Choose the right cloud high availability solution. After a brush with the wind spirit, the enchanted forest is set ablaze by the fire spirit. As the fire spirit spreads chaos, and fire, Elsa charges off with icy blasts to cool the fire and calm this spirit. In her zeal, Anna runs into the fire behind her sister and has to be saved. When at last the two are reunited, Elsa admonishes her sister- “You can’t just follow me into fire”. The feisty Anna replies, “You don’t want me following you into fire? Then don’t run into fire!” Migrating to the cloud and choosing the right availability solution for you can be stressful enough without complicating it by making unrealistic schedules with untested theories and scenarios. No leader of a deployment team wants his or her team in a fire drill, so don’t knowingly run into one. Create a plan. Establish checkpoints and milestones. Include realistic risk and risk management strategies. Communicate frequently with vendors and partners, and especially with your team. Test well, and understand backup and backout plans. 4. Don’t get stuck in the past re: what you bring in your cloud migration. There is a song woven throughout the movie, “All is Found” with the chilling chorus – “Dive down deep into her sound / But not too far or you’ll be drowned.” Elsa dives down into the deep as the movie peaks and her search and exploration of the past leave her Frozen, her last gasp a burst of flurries to warn and inform her sister. As one of the heads of our Customer Experience Team at SIOS Technology Corp., I have witnessed too many deployments and migrations get stuck in a comparison trap. The phrase goes like this, “In our old data center, we” or “The old system could do that.” It may be true that your old system of fixed systems, dedicated resources, large teams, specific networking, and high cost, high feature SAN storage could do that. (Although, truthfully, sometimes I’ve seen the curtain peeled back and on-premise didn’t really do that either). As you migrate to the cloud, understand what makes sense to mimic in the cloud and what doesn’t. Understand why the system was architected that way on-premises and using the help, “lesson 1, and the learning of lesson 2, make decisions that make sense. Which leads me to the final lesson. 5. There will always be two kingdoms: on-premises and in the cloud. At the end of the movie, Anna becomes queen of Arendelle once ruled by her sister Elsa, while Elsa stays and leads the people of the Northuldra. There is one who stays in or near the forest once surrounded by mystery and cloud, while the other returns to the familiar land. As you consider migration to the cloud and your High Availability strategy, remember there will always be two kingdoms. Your migration strategy would do well to remember that you will always have a need for an on-premise data center to partner with your cloud deployments. Perhaps it isn’t as sprawling as it once was, but not every workload or critical infrastructure can be repurposed and packaged for the cloud. Having an HA solution and strategy that can equip and enable both “kingdoms” is essential. Going to the cloud takes the right team, the right tools and the right solutions, and a strategy and plan to get there, without going through fire. As you migrate to the cloud, be willing to confront the past, understand it, and remember not to get stuck there. And, like the two sisters of Disney’s Frozen II, you’ll do well to remember every beautiful enterprise story has two sides, on-premise and cloud just might be yours. — Cassius Rhue, VP, Customer Experience Reproduced with permission from SIOS
August 2, 2020	Why is AWS EC2 Application Monitoring So Hard? Why is AWS EC2 Application Monitoring So Hard? Congratulations! You’ve migrated your core applications to the AWS cloud. Or, you are developing new “cloud-native” applications and hosting them in the cloud. Perhaps you are taking advantage of Amazon EC2’s scalability and its elastic architecture. Either way, you now want to ensure that those applications stay up and running, or that you are alerted quickly if and when something happens. Because something will happen. Our customer data shows that companies using only three EC2 instances experience downtime at least once a month. That means unhappy users unable to access their applications. You need a monitoring solution to tell you what’s going on. How to narrow down EC2 application monitoring solutions The first step in your search for the perfect EC2 monitoring solution should be to understand your requirements and your own technical capabilities. Monitoring solutions are not all alike. Are you interested in a feature-rich solution that monitors a wide array of systems? Or one that focuses on a core set of systems, such as your EC2 environment? What do you want to do with the output from your application monitoring solution? Do you want as much information as possible to help your developers’ troubleshoot issues? Or are you looking for quick alerts and assistance in remediating from any failures? And what is your technical appetite to install and manage another application? Do you love scripting? Or do you want something that is “set-it-and-forget-it”? A search for “application performance monitoring solutions” on Google returns 1,170,000,000 results! Jump into the Amazon AWS Marketplace and you’ll find 453 products listed in the DevOps – Monitoring category. Having a clear sense of your requirements and your own technical capabilities will help you narrow down your search. Monitoring applications running on Amazon EC2 with Amazon CloudWatch or other APM solutions If you are hosting your applications on Amazon EC2, then you might consider using Amazon CloudWatch. How familiar are you with standard and custom metrics? You should know that you need quite a lot of technical expertise to run Amazon CloudWatch properly. Amazon CloudWatch is a great solution for users who need data and actionable insights to respond to system-wide performance changes, optimize resources and a unified view of their operational health. But this all comes at a price in terms of the knowledge and experience needed to configure and manage Amazon CloudWatch properly. Another choice is for you to evaluate and acquire one of the many commercially available application performance monitoring (“APM”) solutions on the market, such as from AppDynamics, Datadog, Dynatrace, or New Relic. But keep in mind your requirements. How broadly do you need to monitor? And what do you intend to do with that information? Are you ready to be overwhelmed with alerts? And be aware that many APM solutions do nothing to help you recover beyond pinpointing the issue. You still have to drop everything to manually restart services or reboot your instances. Monitor applications running on Amazon EC2 using SIOS AppKeeper But there is another way. SIOS AppKeeper is a SaaS service that can be configured to automatically discover any EC2 instances and their services. It then automatically take any number of actions if and when downtime is experienced. So instead of getting alerts that something is wrong, you get notified that something happened and was automatically addressed. SIOS AppKeeper starts at only US $40 per instance per month. We invite you to view this short video to see how easy it is to install and use AppKeeper. Why is AWS EC2 Application Monitoring So Hard? One of our customers, Hobby Japan, a publishing company in Tokyo, was initially using Amazon CloudWatch but their understaffed IT team couldn’t respond fast enough to alerts. They wanted to leverage automation and moved to SIOS AppKeeper. Since moving to AppKeeper they haven’t experienced any issues or unexpected downtime with their EC2 instance. Here’s a link to a case study on Hobby Japan. Monitoring your cloud applications shouldn’t be a full-time job. You want a monitoring solution that is easy to install and use, doesn’t overwhelm you with alerts, and hopefully takes care of systems impairments automatically. We encourage you to try a 14-day free trial of SIOS AppKeeper by signing up here. Article reproduced with permission from SIOS