Integration of SAP ASE with Prominent Cluster Solutions
This article is the continuation of "Business Continuity with SAP ASE – Server Availability Solutions (1/2)". It details SAP ASE integration with major vendors cluster solutions.
Symantec Veritas Cluster Server:
Symantec Veritas Cluster Server (VCS) provides cross platform cluster software (for HP-UX, IBM AIX, Linux, Microsoft Windows, Oracle Solaris and VMware).
It has Business Continuity solutions for both SAP ERP [3] and SAP ASE.
Symantec ships two agents for SAP ASE with Veritas Cluster Server to monitor/start/stop SAP ASE resources:
A quick overview of Symantec Veritas Cluster Server for SAP ASE is given in [3a]
The resource dependencies define the order of starting (or stopping) the resources inside a service group.
To start the Sybase database service a bottom-up order is used. The first resource to be started is the dgres resource (of “DiskGroup” resource type). Then several logical volumes are started (sybasedg_vol for data and log devices of the database server and for the SAP ASE distribution). The network interface for the SAP ASE database server is started via nicres and ipres resources. Then file systems are mounted via several “Mount” resource types. Once all the resources are brought online, the database server can be started. The Backup Server is started after the datasever is started.
Stopping the resource for a graceful shutdown or a planned failover uses a top-down order.
Configuration steps:
Setting up the cluster configuration can be done with a GUI (Cluster Manager, Java console) or using the command line. Using the command line, you have to:
Failover/failback processes:
A failover process can be a planned event or triggered by an outage. In case of a planned failover, the administrator (DBA or system administrator) chooses to move the SAP ASE service from a physical node onto another. Following graceful procedure is executed:
On the target node (the node chosen by the administrator to host the failover database), the above sequence is reversed.
For unplanned failover events, the same sequence occurs. Nevertheless, in case of a sudden failure there are noticeable differences:
Failling back to the original node is a planned process and follows the planned failover process.
Symantec provides a lot of documentation for VCS (generic and platform specific). For instance, implementation example of VCS for SAP ASE on AIX can be downloaded at [4] and [5].
HP Serviceguard:
HP Serviceguard is available on HP-UX and Linux. SAP ASE can be integrated with HP Serviceguard in two ways:
Configuration steps for standalone database server:
The Sybase ASE Toolkit for Serviceguard consists of a shell script that is used to start, stop, and monitor a single-instance of Sybase ASE. SAP ASE binaries should be installed on a shared directory accessible by all nodes.
Registering of SAP ASE as an HP Serviceguard package is done via command line.
Following commands will register ASE0 database server configuration in the cluster; enable ASE0 on physical nodes (here node1 and node2) and start the database server.
cmapplyconf –p ASE0.conf
cmmodpkg –e –n node1 –n node2 ASE0
cmmodpkg –e ASE0
Check [8] for more information.
Failover/failback processes:
For a planned failover, run following:
IBM PowerHA SystemMirror:
PowerHA SystemMirror is the Business Continuity solution from IBM. It was previously known as IBM HACMP. IBM PowerHA SystemMirror does not provide specific agent (Smart Assist) for SAP ASE yet. SAP ASE can be integrated into a IBM PowerHA cluster as an application resource. PowerHA SystemMirror uses the term “application server” for application resource like database server.
The administration of cluster resources is done with AIX smitty utility.
For instance, in order to register a SAP ASE database server use “Configuration-->HACMP Extended Resources Configuration--> Configure HACMP Application Servers-->Add an Application Server” menu of smitty.
See documentation [10] and [11].
Microsoft Cluster Server:
Installation of SAP ASE with Microsoft Cluster Server is described in SAP Note 1651052 - SYB: MS Cluster: DB instance for failover. SAP installations for SAP ASE provide installation options for a Microsoft Cluster environment as of Software Logistics Toolset 1.0 SPS 06.
ORACLE SUN Cluster:
SUN Cluster uses cluster agents to start/stop/monitor application resources. You can use the SYBASE cluster agents provided by ORACLE or your custom agents for ASE. Custom agents are known as Generic Data Services (GDS).
Availability of ORACLE SUN agents for SYBASE ASE depends on the version of SUN Cluster:
Configuration steps:
I have seen both types of agents on customer sites. Both resource types rely on other cluster resources that can be imported/exported by all the nodes of the cluster:
For example, below are the steps for registering a database server with the provided agent “SUNW.sybase”. Database server corresponds to ASE-resource-name resource and belongs to a resource-group-name resource group.
# clresource create -g resource-group-name
-t SUNW.sybase
-p Environment_File=environment-file-path
-p Adaptive_Server_Name=adaptive-server-name
-p Backup_Server_Name=backup-server-name
-p Text_Server_Name=text-server-name
-p Monitor_Server_Name=monitor-server-name
-p Adaptive_Server_Log_File=log-file-path
-p Stop_File=stop-file-path
-p Connect_string=user/passwd
-p resource_dependencies_offline_restart=storageplus-resource
-p Wait_for_Online=TRUE
-p DB_Wait_List=db1, db2, ...
-p Restart_type=RESOURCE_RESTART|RESOURCE_GROUP_RESTART
-p Custom_action_file=filepath ASE-resource-name
Below is the equivalent method for registering a database server resource via GDS. Database server corresponds to ASE-resource-name resource and belongs to a resource-group-name resource group.
clresource create -g resource-group-name
-t SUNW.gds
-p Validate_command="validate-file-path"
-p Scalable=false -p Start_timeout=120
-p Stop_timeout=120 -p Probe_timeout=120
-p Port_list="2222/tcp"
-p Start_command="start-file-path"
-p Stop_command="stop-file-path"
-p Probe_command=”monitor-file-path"
-p Child_mon_level=0 -p Network_resources_used=logical_node
-p Failover_enabled=TRUE -p Stop_signal=9 ASE-resource-name
Failover/failback processes:
To failover a database server resource, the entire resource group to which it belongs to must be switched. “clresourcegroup switch” Solaris command is used for failover/failback purposes. It does the following:
Red Hat Enterprise Linux with High Availability Add-on:
Red Hat provides an agent for SYBASE ASE for Red Hat Enterprise Linux with High Availability Add-on. The agent is called, “ASEHAagent - Sybase ASE Failover Instance”. A typical “SYBASE” service contains three resources:
SYBASE ASE service (enable, disable, restart, and relocate) can be executed using a:
In collaboration with Red Hat, SAP has started to improve the official integration of SYBASE ASE. For more information check [14] and [15].
SUSE Linux Cluster Solution:
There is no support for Sybase ASE 15.7 yet, but customers can add their own live check scripts for SAP Sybase ASE. In collaboration with Novel, SAP has started to develop the official integration of SAP Sybase ASE. For more information, refer to the white paper, "SAP Made High-Available on SUSE Linux Enterprise Server for SAP Applications" on http://www.novell.com/sap.
In my next post, I will describe SAP ASE with HA option. The SAP ASE with HA option is built on top of the vendor failover cluster solutions outlined in this post. It ensures quicker failover and additional features pertinent to database HA needs.
References:
General information:
[1] “Competitive Landscape: Clustering Software Market, Worldwide” GARTNER December 2012. http://www.symantec.com/hk/content/en/us/about/media/industryanalysts/Gartner_Clustering_Software_Ma...
[2] "High availability and disaster recovery: concepts, design, implementation", Klaus SCHMIDT, Springer 2006, ISBN 3540244603, 9783540244608
Symantec Veritas Cluster Server:
[3] Data Sheet: Clustering - Veritas™ Cluster Server for SAP Solutions
http://eval.symantec.com/mktginfo/enterprise/fact_sheets/b-datasheet_vcs_for_sap_solutions_01_2008_1...
[3a] High Availability for Databases Protecting Sybase Databases with Veritas™ Cluster Server
http://eval.symantec.com/mktginfo/enterprise/white_papers/b-ha_for_sybase_db_with_vcs_hadr_WP_141795...
[4] Sample configuration for a Sybase service group on AIX systems Article: HOWTO17258
http://www.symantec.com/docs/HOWTO17258
[5] VCS Sybase agent 6.0 for AIX
http://www.symantec.com/business/support/resources/sites/BUSINESS/content/live/DOCUMENTATION/5000/DO...
HP Serviceguard:
[6] Managing Serviceguard Eighteenth Edition http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02437444/c02437444.pdf
http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02048903/c02048903.pdf
[7] Managing Serviceguard Extension for SAP Version B.05.10
http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c03253067/c03253067.pdf
[8] Using the Sybase ASE Toolkit in a Serviceguard Cluster on HP-UX
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02496246/c02496246.pdf
[9] HP Serviceguard Enterprise Cluster Master Toolkit User Guide
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c03251454/c03251454.pdf
Using Easy Deployment in Serviceguard and Metrocluster environments on HP-UX 11i v3 - (March 2012)
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c03209367/c03209367.pdf
IBM PowerHA SystemMirror:
[10] IBM PowerHA SystemMirror documentation
http://public.dhe.ibm.com/software/dw/aix/au-powerhaintro-pdf.pdf
http://www-03.ibm.com/systems/power/software/availability/index.html
http://www-03.ibm.com/systems/power/software/availability/aix/resources.html
http://publib.boulder.ibm.com/infocenter/aix/v7r1/topic/com.ibm.aix.powerha.navigation/powerha_pdf.h...
[11] PowerHA resource at SCN: http://scn.sap.com/docs/DOC-8761
ORACLE SUN Cluster:
[12] Sun Cluster 3.5 - Data services - Sybase ASE - http://docs.oracle.com/cd/E18728_01/pdf/821-2908.pdf
[13] Sun Cluster 4.1 - Howto Use Oracle Solaris Cluster Administration Commands to Create a Highly Available ServiceThat Uses the GDS p.187 - http://docs.oracle.com/cd/E29086_01/pdf/E29471.pdf
Red Hat Cluster Suite:
[14] Red Hat Enterprise Linux Cluster Admin Guide
https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Cluster_Administratio...
[15] Deploying Highly Available SAP Servers using Red Hat Clustering
http://www.redhat.com/resourcelibrary/reference-architectures/Deploying-Highly-Available-SAP-Servers...
SAP:
[16] SAP Sybase Adaptive Server Enterprise Getting Started with the Sybase Database and the SAP System
[17] 1650511 SYB: High Availability Offerings with Sybase ASE
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