|July 22, 2020||
Backup, replication, and high availability (HA) clustering are fundamental parts of IT risk management, and they are as indispensable as the wheels on a car. Replication is also essential to IT data protection.
Backup and HA Cluster Environments Are Not Mutually Exclusive
While backup, replication, and failover are all important, there are key distinctions among them that need to be understood to ensure they are applied properly.
For example, while you can use replication to maintain a continuously up-to-date copy of data, without considering it in the larger data protection environment, you will also copy problem data (such as virus-infected data).
In such cases, a backup is essential to bring the data back to the last known good point. By performing replication, you can access the image replicated immediately before the system failure (= RTO / RTO is superior) in a way that simply storing data by generation and supporting it in an eDiscovery type model cannot.
Therefore, SIOS Protection Suite includes both SIOS LifeKeeper clustering software and DataKeeper replication software. SIOS LifeKeeper is an HA failover cluster product that monitors application health and orchestrates application failover and DataKeeper is block-based storage replication software. However, just because it is an HA cluster does not mean that backup is unnecessary. Consider the precautions and points to note when backing up in an HA cluster environment using SIOS Protection Suite.
Five Points of Backup in a High Availability Clustering Environment
Consider the following five points as the target of backup acquisition:
Backup the OS
To back up the OS it is common to use a standard OS utility or third-party backup software. However, since there is no special consideration for the high availability environment, we will not cover it here.
Backup the SIOS Protection Suite Clustering Software
SIOS Protection Suite includes SIOS LifeKeeper / DataKeeper program can also be obtained with the OS standard utility or third-party backup software, but if the program disappears due to a disk failure etc. without intentionally backing it up, you need to reinstall it. There will probably be some people who think about the dichotomy of doing so.
Backup the SIOS Protection Suite Configuration Information
SIOS LifeKeeper comes with a simple command called lkbackup that enables you to backup the configuration information. lkbackup can be run on SIOS LifeKeeper and related resources and will not impact running services.
This command can be executed in the following three main cases.
If you back up the configuration information with lkbackup, even if the configuration information disappears due to a disk failure or if the configuration information is corrupted due to an operation mistake, etc.) you can quickly return to the original operational state.
Backup Operational Programs
Although backing up operation programs refers to backing up the business applications being protected in your HA cluster, it is possible to create and restore a backup image using the OS standard utility or third-party backup software as in 1. and 2 above.
Backup Business Application Data
In an HA cluster environment, shared storage that can be accessed by both active and standby servers is provided. During normal operation, the shared storage is used by the active cluster node. Application data (for example, database data) is usually storage in this shared storage, but the following points should be kept in mind when backing up this storage.
For shared storage configuration
When acquiring a backup of the data located in a SANless cluster configuration with storage shared by both the active cluster node and the standby system, the data can only be accessed from the active system (the standby system cannot access the data). As a result, the backup is also active. In this case, ensure that there is sufficient processing power to handle a failover and backup restore scenario.
For data replication configuration
In the case of the data replication configuration, the backup from the operating system is the basic, but by temporarily stopping the mirroring and releasing the lock, the backup can also be executed on the standby system side. However, in this case, the data is temporarily out of sync.
Backing up a cluster node from an external backup server
To perform a cluster node backup from an external backup server, use either the virtual or real IP address of the cluster node. The points to note in each case are as follows.
Backing up using the virtual IP address of a cluster node
From the backup server’s perspective, backup is executed to the node indicated by the virtual IP address of LifeKeeper. In this case, the backup server does not need to be aware of which node is the active node.
Backing up using the real IP address of the cluster node
From the backup server’s perspective, the backup is performed to the real IP address without using the virtual IP address of LifeKeeper. Since the shared storage cannot be accessed from the standby cluster node, the backup server and client must check which node is the active node.
Combining backup, replication, and failover clustering in a well-tested and verified configuration backup is indispensable. Using perform sufficient operation verification in advance on the user side.
Reproduced with permission from SIOS
|July 18, 2020||
High Availability Software is Insurance Against SAP Downtime
We all need to buy insurance – for our cars, our houses, our lives. Nobody likes to pay money for a service that we hope we never have to use. But we all know that we should have it just in case. Most people either put off insurance until something awful happens, buy the cheapest, or actually do their homework and buy it from someone they trust. This last group usually fares the best.
|July 17, 2020||
6 Common Cloud Migration Challenges
As a software engineer for customer experience with SIOS, I often help companies who are migrating their on-premises high availability clustering environments to the cloud.
Cloud migration is a process, not a destination. When we engage a customer transitioning to the cloud, it’s often late in the planning process, which isn’t ideal, but not unusual in a cloud migration. Below are six cloud migration challenges we see all too frequently.
Executing a successful cloud migration requires input from all stakeholders. High availability and disaster recovery are core aspects of any enterprise workload. Whether SIOS is already part of your current system or will be part of your future cloud migration, get us involved!
-Harrison Howell, Software Engineer for Customer Experience
Reproduced with permission from SIOS
|July 15, 2020||
SIOS Protection Suite for Linux Version 9.5 is Here!
We are proud to announce the availability of SIOS Protection Suite for Linux version 9.5. This product introduces advanced automation and application-aware monitoring making it the most comprehensive, out-of-the-box SAP S/4HANA clustering software in the industry.
We know what a hassle it is to try to manually build an SAP S/4HANA cluster, making sure that all of the HANA services will failover to the right locations and start up in the right order. Hours of scripting, testing, and aggravation. And the stakes are high. Getting it wrong can mean failover doesn’t happen or worse – downtime, data loss, lots of aggravated users calling.
That’s why we added intelligent application availability for two-node SAP S/4HANA database configurations that are using HANA System replication (HSR). We’ve built this release to take the hassle and risk out of building and managing a cluster.
SIOS Protection Suite v9.5 Automates and Monitors
Starting from easy, wizard-driven configuration that actually validates your input. No hours of manual scripting… or searching for a mistaken keystroke when things don’t go right.
It monitors all the processes in the HANA stack from the application to the hardware, servers, and network – not just checking that the server is operational like other clustering software.
And unlike other clustering solutions that trigger a failover for everything, if SIOS Protection Suite detects an issue, it automatically takes the appropriate recovery action – whether that’s simply restarting a service, recovering on the node that is in service or orchestrating a failover to a secondary node.
Speaking of failover orchestration, it will automatically ensure that SAP-specific best practices are maintained throughout. For example, it makes sure that on failover or switchover, ASCS is never on a server with the primary application or on the same server with the ERS.
If the wizard-driven configuration isn’t easy enough, we also added a new command-line interface (CLI) cloning feature that lets you deploy a SIOS cluster simply by importing the CLI instructions for configuration. You can also export the CLI instructions of an existing cluster to create a clone of it.
Now with SIOS Protection Suite for Linux, you can create a high availability cluster quickly and easily to protect any application. This includes SQL Server, Oracle, SAP and S/4HANA, from downtime and disasters.
Reproduced with permission from SIOS
|July 14, 2020||
EC2 Monitoring Best Practices: Using SIOS AppKeeper to Protect NGINX Webservers on Amazon EC2