High-Availability Messaging: Clustering Novell GroupWise ® Stephen C. Payne Senior Consultant Protocom Development Systems Eric Wing Partner and Integration Specialist Tenacious Integration Services Bryon Griffin Technology Specialist Novell, Inc. Scott McCallum Sr. Consultant Novell, Inc.

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Definition of a Cluster A cluster is a combination of hardware and software that enables you to connect two or more servers, which thereafter act as a single system A cluster is typically connected to a storage area network (SAN) Clusters provide continuous access to cluster resources and services When a cluster server fails, the services and resources it was providing are distributed to the surviving cluster servers

Storage Area Networks Definition A dedicated network connecting servers and storage peripherals Consists of servers, external storage devices, adapters, hubs, switches, etc. Combines the flexibility, manageability, and saleability of networks with the high-bandwidth and reliability of storage

Novell Cluster Services ™ Definition A collection of Novell NetWare ® servers  Provides improved availability  Acts as a single system  Provides scalability  Provides manageability  Utilizes storage area networks

Novell Cluster Services Terminology Node Cluster resource  Load script  Unload script  Preferred node list  Policies Cluster-enabled volume Master node Slave node Failover  Novell FAN-OUT-FAILOVER ™ Failback Epoch Quorum membership Quorum timeout Protocol information  Heartbeat  Masterwatchdog  Tolerance  Slavewatchdog

Novell Cluster Services Benefits All nodes active Central administration Transparent client reconnect Up to 32 nodes Fully integrated and managed in Novell eDirectory ™ FAN-OUT FAILOVER Web- (Novell Remote Manager) and Novell ConsoleOne ® -based administration

Novell Cluster Services Limitations Manual load balancing Shared storage recommended—required for Novell GroupWise ® (GW) TCP/IP-based only NetWare 5.x and 6.x A NetWare cluster cannot span multiple eDirectory trees

What’s New in GW6 SP1 for Clustering? Enhanced support for Virtual Servers (VS) by most GW components  Post Office Agent (POA) can use Universal Naming Convention (UNC) to software distribution directory  Home switches can use UNC path with VS GW Notify auto-reconnects Enhanced backup and restore with GWTSA Agent installation program includes Novell Cluster Services option  Should add the /cluster and /IP switches manually

What’s Changed Since the Last BrainShare Clustering GW Session? Most recommendations still apply When using GW6 agents (GWIA, WebAccess), you must load the agent in the same memory space as the MTA Load DSAPI in the same address space as MTA for eDirectory user synchronization event to run

GroupWise 6 Installation Notes When installing agents, option exists to “Configure Agents for Clustering”  /HOME switch uses legacy volume syntax instead of UNC  AUTOEXEC.NCF file isn’t updated Remember to add the /CLUSTER switch to the POA start-up file

GroupWise 6 SP1 Installation Notes All agents have been modified to understand virtual servers When installing, option exists to “configure agents for clustering”  Uses UNC paths again, since agents now understand the virtual servers  Automatically adds the /CLUSTER switch

Cluster Resources Defined on Our Demonstration System PDPO1  Primary domain with post office 1 PO2  Post office 2 PO3  Post office 3 GWIA  GroupWise Internet Agent and domain WEBAGENT  WebAccess gateway and domain WEB  Novell Enterprise Web Server DHCPSRVR  DHCP server HOME  Use home directory volume APPS  Apps volume PUBLIC  Public volume

Novell Cluster Services Components ResourceIPPreferredFailover PDPO , 3 PO , 4 PO , 1 GWIA , 2 WEBAGENT , 4 WEB , 1 DHCPSRVR , 2 HOME , 3 APPS , 1 PUB , 2

NetWare Cluster Services GroupWise Design considerations  Follow Novell-recommended GroupWise design guidelines for centrally located system  Some cluster-specific considerations Name resolution considerations  Virtual servers—do not use underscore (“_”)  All virtual servers in DNS  All virtual servers in HOSTS files on cluster nodes  Best to use short virtual server names

Planning the System Layout Port planning

Installing GroupWise In the Cluster Plan the GroupWise system layout Create the GroupWise volumes Create cluster volumes and cluster resources Mount volume hosting the primary domain and first post office Install GroupWise 6 creating GW System, primary domain, and first PO

Installing GroupWise In the Cluster (cont.) Mount the remaining GroupWise volumes Create additional domains and post offices Install GW agents to GroupWise volumes running an MTA or POA Create and configure the GWIA gateway Designate a compatible web server or install and configure Novell Enterprise Web Server Create and configure the WebAccess gateway

Domain Configuration Primary domain, routing domain, Resource domains Cluster-enabled volume Locate agents, start-up files, and file structure on the cluster volume  No SYS volume dependencies gives the greatest flexibility

DOMAIN and First PO Load Script NSS /POOLACTIVATE= PoolName MOUNT volume VOLID=x CVSBIND ADD virtual ncp server x.x.x.x NUDP ADD virtual ncp server x.x.x.x ADD SECONDARY IPADDRESS x.x.x.x LOAD ADDRESS SPACE= DSAPI LOAD ADDRESS SPACE= SYSTEM\STARTUP.MTA LOAD ADDRESS SPACE= SYSTEM\STARTUP.POA PROTECTION RESTART

DOMAIN and First PO Unload Script UNLOAD ADDRESS SPACE = DSAPI UNLOAD ADDRESS SPACE = GWMTA UNLOAD ADDRESS SPACE = GWPOA DELAY x UNLOAD KILL ADDRESS SPACE = DEL SECONDARY IPADDRESS x.x.x.x NUDP DEL virtual ncp server x.x.x.x CVSBIND DEL virtual ncp server x.x.x.x NSS /POOLDEACTIVATE=PoolName /OVERRIDE=QUESTION

Post Office Configuration Cluster volume vs. cluster resource Locate everything on the cluster volume POA startup file modifications  POA /CLUSTER switch  POA /IP switch Assign unique ports to each POA within the cluster For best performance, use new caching mode

Post Office Resource Load Script NSS /POOLACTIVATE= PoolName MOUNT volume ADD SECONDARY IPADDRESS x.x.x.x LOAD ADDRESS SPACE= SYSTEM\STARTUP.POA PROTECTION RESTART Cluster-enabled volume is optional—include necessary commands if cluster-enabling the volume

Post Office Resource Unload Script UNLOAD ADDRESS SPACE = GWPOA DELAY x UNLOAD KILL ADDRESS SPACE = NSS /POOLDEACTIVATE=PoolName /OVERRIDE=QUESTION DEL SECONDARY IPADDRESS x.x.x.x

Cluster-Enabling GWIA Domain Considerations Domain volume must be cluster-enabled Configure the domain and the GWIA as a single cluster resource (the cluster-enabled volume) Configure the domain and the GWIA on the same volume on the SAN Install the domain using a UNC path through the virtual server or a drive mapped to the cluster-enabled volume GWIA must run in the same memory space as the MTA

Cluster-Enabling GWIA NetWare Loadable Module ™ (NLM ™ ) Considerations Each node’s SYS volume  Must install the GWIA multiple times or copy the NLM  OR, consider placing the startup files on the shared volume to minimize administration On the shared volume with the domain  Don’t forget where the NLMs are when you patch

Cluster-Enabling GWIA Installing the GWIA Install through the UNC path with the virtual server Modify the startup files  /home=Volume:\path  /dhome=Volume:\path Confirm the EXEPATH.CFG file (for snap-ins)  UNC path using virtual server

Cluster-Enabling GWIA Protected Memory Domain MTA—use protected memory if any chance two MTAs will be on the same node GWIA—does not need protected memory unless multiple GWIAs in the cluster  GW6 GWIA must be in the same address space as its MTA Commands  LOAD ADDRESS SPACE= LOAD ADDRESS SPACE=NAME  PROTECTION RESTART NAME  UNLOAD ADDRESS SPACE=  PROTECTION

Cluster-Enabling GWIA Cluster Resource Never have two resource objects for the same logical resource  i.e., one for the volume and one for GroupWise Add the GroupWise commands to the cluster-enabled volume cluster resource object Copy commands from the template, but do not use the template for the GWIA

Cluster-Enabling GWIA Name Resolution Considerations Must resolve virtual server name (IP name resolution)  CVSBIND propagates to SLP and is highly recommended  DNS if your DNS implementation supports “_”  NDS—Do not forget about context  HOSTS files  NWHOSTS files (administrator workstation)

Cluster-Enabling GWIA Load Script Normal cluster-enabled volume commands  Add IP address  Activate and mount volume  NUDP ADD command Add CVSBIND command for name resolution Load GroupWise domain commands using protected memory Load GWIA in same memory space as its MTA Protection restart

Cluster-Enabling GWIA Unload Script Unload GWIA using protected memory Unload GWMTA using protected memory Add a pause to allow modules to unload Kill the address space Normal cluster-enabled volume unload commands  Stop CVSBIND advertisement  Dismount and deactivate the volume  Stop NUDP response  Delete the secondary IP address

Cluster-Enabling GWIA Miscellaneous Considerations Configure all domain links to be TCP/IP within the cluster/LAN Configure the GWIA post office links TCP/IP Firewall considerations  Allow services incoming to secondary IP address  Allow services outgoing using each servers primary IP address

GroupWise Domain for WebAccess Use a separate cluster-enabled volume Create a dedicated domain for WebAccess gateway (GWINTER)

Novell Enterprise Web Server Configure a hardware virtual server using web server administrator  Use web browser to point to  Use TCP/IP address assigned to cluster- enabled volume  TCP/IP port 80 (443 for SSL)  Document directory should be placed onto cluster-enabled volume Assign document directory as a “public directory”  Restrict access if SSL is being used Active/active web server vs. active/passive web server Edit SYS:SYSTEM\NSWEB.NCF Duplicate configuration on each web server DO NOT manually start/stop web server—use cluster-resource to control web server

Installation of WebAccess Initial install should include Java servlets and WebAccess agent (GWINTER)  All Java servlets located on each node’s SYS: volume  Install documents to default (SYS:\NOVONYX\SUITESPOT\DOCS) directory  Copy DOCS directory to hardware virtual server’s document directory on the shared volume  Install servlets only on each node  Copy NLMs to each additional node  Note: for Novell WebPublisher, cache location should be changed to cluster-enabled volume  STRTWEB.NCF modifications Protected memory Move to cluster-enabled volume

WebAccess Cluster Load Script NSS /POOLACTIVATE=PoolName MOUNT GWWEB1 VOLID=x CVSBIND ADD virtual ncp server x.x.x.x NUDP ADD virtual ncp server x.x.x.x ADD SECONDARY IPADDRESS x.x.x.x LOAD ADDRESS SPACE=addrspace DELAY XX vol:path\STRTWEB.NCF [STRTWEB.NCF must call GWINTER in protected memory in the same space as GWMTA] PROTECTION RESTART addrspace

WebAccess Cluster Unload Script UNLOAD ADDRESS SPACE=addrspace GWINTER UNLOAD ADDRESS SPACE=addrspace GWMTA DELAY xx UNLOAD KILL ADDRESS SPACE=addrspace DEL SECONDARY IPADDRESS x.x.x.x NUDP DEL virtual ncp server x.x.x.x CVSBIND DEL virtual ncp server x.x.x.x NSS /POOLDEACTIVATE=PoolName /OVERRIDE=QUESTION

WebAccess Failover Characteristics Time for failover and migration End-user experience

Cluster Resources Running on Preferred Nodes Server1 PDP01 WEBAGENT APPS Server2 P02 WEB PUB Server3 PO3 DHCPSRVR Server4 GWIA HOME

Server1 PDP01 WEBAGENT APPS Server2 P02 WEB PUB Server3 PO3 DHCPSRVR Server4 GWIA HOME What Happens When a Node Fails?

Server1 PDP01 WEBAGENT APPS GWIA Server2 P02 WEB PUB HOME Server3 PO3 DHCPSRVR Server 4 down FAN-OUT FAILOVER

GroupWise Target Service Agent (GWTSA) and Clustering A GroupWise-specific API Works with other backup software (e.g., Veritas BackupExec for NetWare) Standard GroupWise post office and domain directory structures/files backed up Currently only available for NetWare platform

GWTSA and Clustering (cont.) GWTSA must be installed and loaded on each server to be backed up GWTSA cannot currently run in protected memory Use /HOME switch  Add path for every domain on a cluster-enabled volume that may fail over to a particular server  Add path for every post office on a cluster-enabled volume that may fail over to a particular server

GWTSA and Clustering (cont.) GWTSA checks availability of each location All available domain and post office files are backed up If a location becomes unavailable during backup, backup should be restarted  Currently no method to restart backup from a checkpoint position Restore data to a currently mounted location

Need More Info? June 2001 AppNotes ® ( Novell Press Novell’s Guide to Storage Area Networks and Novell Cluster Services by Payne and Wipfel ISBN /tswizard/