196 lines
9.6 KiB
HTML
196 lines
9.6 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
|
||
|
|
<title>Cluster APIs--Introduction</title>
|
||
|
|
<!-- Begin Header Records ========================================== -->
|
||
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
||
|
|
<!-- US Government Users Restricted Rights -->
|
||
|
|
<!-- Use, duplication or disclosure restricted by -->
|
||
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
||
|
|
<!-- CLUST1A SCRIPT A converted by B2H R4.1 (346) (CMS) by NLJONES at -->
|
||
|
|
<!-- RCHVMX on 24 Feb 1999 at 15:32:00 -->
|
||
|
|
<!-- End Header Records ============================================= -->
|
||
|
|
<!-- -->
|
||
|
|
<!-- -->
|
||
|
|
<!-- -->
|
||
|
|
<!-- Begin Developer Note ========================================== -->
|
||
|
|
<!-- NOTE: If you are adding, changing, or removing ANY requirements -->
|
||
|
|
<!-- for this API chance are good that the GUI code need to change -->
|
||
|
|
<!-- also. The Cluster GUI code is built on top of this API and it -->
|
||
|
|
<!-- does a certain amount of explicit and implicit validation -->
|
||
|
|
<!-- checking of user data prior to the API call being made. Please -->
|
||
|
|
<!-- have the Cluster GUI developer check the -->
|
||
|
|
<!--/as400/v5r4m0.guix/cur/cmvc/java.pgm/ugcl.guix/com/ibm/as400/opnav/ugcl/ClGuiActionsManager.java/ClGuiActionsManager.java -->
|
||
|
|
<!-- part to determine if any Cluster GUI code changes are needed. -->
|
||
|
|
<!-- End Developer Note -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<!--Java sync-link ================================================== -->
|
||
|
|
<script type="text/javascript" language="Javascript" src="../rzahg/synch.js">
|
||
|
|
</script>
|
||
|
|
|
||
|
|
<a name="Top_Of_Page"></a>
|
||
|
|
|
||
|
|
<h2>Cluster APIs--Introduction</h2>
|
||
|
|
|
||
|
|
<p>An iSeries<SUP>(TM)</SUP> <strong>cluster</strong> is defined as a collection of complete
|
||
|
|
systems that work together to provide a single, unified computing capability. A
|
||
|
|
cluster is identified by a 10-character name. The cluster is comprised of one
|
||
|
|
or more <strong>cluster nodes</strong>. A cluster node is an iSeries system
|
||
|
|
that is a member of a cluster. Each cluster node is identified by an
|
||
|
|
8-character cluster node identifier that is associated with a set of IP
|
||
|
|
addresses representing an iSeries system.</p>
|
||
|
|
|
||
|
|
<p>Cluster communications running over IP provides the communications path
|
||
|
|
between cluster services on each node in the cluster. Cluster Resource Services
|
||
|
|
requires that the loopback IP address on each node be active. The set of
|
||
|
|
cluster nodes that have been configured for the cluster is referred to as the
|
||
|
|
<strong>cluster membership list</strong>.</p>
|
||
|
|
|
||
|
|
<p>Whenever communication with a node is lost but node or cluster resource
|
||
|
|
services failure cannot be guaranteed, a cluster becomes
|
||
|
|
<strong>partitioned</strong>. A cluster may be separated into multiple
|
||
|
|
partitions. While partitioned, some cluster operations may be restricted.</p>
|
||
|
|
|
||
|
|
<p>High availability through clustering is accomplished through the
|
||
|
|
implementation of <strong>resilient resources</strong>. A resilient resource is
|
||
|
|
any system resource supported by clustering that is available on more than one
|
||
|
|
node in the cluster. If a node in the cluster that is the primary access point
|
||
|
|
for a particular set of resilient resources should fail, another node that is
|
||
|
|
defined to be the backup for that set of resources will become the access
|
||
|
|
point. The definition of the relationship between the nodes associated with a
|
||
|
|
set of resilient resources is found in the cluster resource group (CRG) object.
|
||
|
|
Cluster resource groups are distributed and coordinated across the nodes in the
|
||
|
|
cluster. Cluster resource groups contain a <a href=
|
||
|
|
"clust3a1TOC.htm#header_2">recovery domain</a>.</p>
|
||
|
|
|
||
|
|
|
||
|
|
<p><img src="delta.gif" alt="Start of change"><strong>
|
||
|
|
Cluster Administrative Domain</strong> will allow a cluster administrator to maintain a
|
||
|
|
consistent operational environment across the cluster or a subset of the cluster.
|
||
|
|
<img src="deltaend.gif" alt="End of change"></P>
|
||
|
|
<br>
|
||
|
|
|
||
|
|
|
||
|
|
<h3><a name="Header_3">Example Source Code</a></h3>
|
||
|
|
|
||
|
|
<p>Example control language command source has been provided in the base
|
||
|
|
operating system option 7 (Example Tools Library, QUSRTOOL). These commands
|
||
|
|
interface to the Cluster Resource Services APIs. See member, TCSTINFO, in file
|
||
|
|
QUSRTOOL/QATTINFO for more information.
|
||
|
|
<img src="delta.gif" alt="Start of change"> i5/OS<SUP>(R)</SUP> supported CL
|
||
|
|
commands can be found by doing "GO CMDCLU" from the command entry screen.
|
||
|
|
<img src="deltaend.gif" alt="End of change"></p>
|
||
|
|
|
||
|
|
<p>In addition, example application cluster resource group exit program source
|
||
|
|
code can be found in the TCSTAPPEXT and TCSTDTAARA members in file
|
||
|
|
QUSRTOOL/QATTSYSC.</p>
|
||
|
|
|
||
|
|
<p>Sample program source has been included which will create the QCSTHAAPPI,
|
||
|
|
QCSTHAAPPO data areas and the QACSTOSDS object specifier file. See member
|
||
|
|
TCSTDTAEXT in QUSRTOOL/QATTSYSC for the source. This is not a complete program
|
||
|
|
as written. Data specific to the application must be added since each
|
||
|
|
application has different resiliency requirements.
|
||
|
|
<img src="delta.gif" alt="Start of change">See
|
||
|
|
<a href="http://www.as400.ibm.com/ha/" target="_blank">High Availability
|
||
|
|
and Clusters</a><img src="www.gif" alt="Link outside Information Center"> for
|
||
|
|
information on making applications highly available and cluster-proven
|
||
|
|
applications. This website also contains more information on QCSTHAAPI data
|
||
|
|
area, QCSTHAAPPO data area, and QACSTOSDS object specifier file.
|
||
|
|
<img src="deltaend.gif" alt="End of change"></p>
|
||
|
|
|
||
|
|
<br>
|
||
|
|
|
||
|
|
|
||
|
|
<h3><a name="Header_31">Terminology</a></h3>
|
||
|
|
|
||
|
|
<p><strong>Access point.</strong><img src="delta.gif" alt="Start of change"> For primary-backup
|
||
|
|
model,<img src="deltaend.gif" alt="End of change"> the primary point of access for
|
||
|
|
a resilient
|
||
|
|
resource. If that resource fails, one of the backup resources will become the
|
||
|
|
primary access point.
|
||
|
|
<img src="delta.gif" alt="Start of change">
|
||
|
|
For peer model, the point of access for a resource. All nodes of type peer, are a
|
||
|
|
point of access for the resource. <img src="deltaend.gif" alt="End of change">
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<p><strong><img src="delta.gif" alt="Start of change">
|
||
|
|
Administrative domain.</strong> Monitors and synchronizes changes to selected resources within a cluster. Cluster administrative domain provides easier management and synchronization of attributes for resources that are shared within a cluster, such as environment variable or user profiles.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<p><strong>
|
||
|
|
Application
|
||
|
|
<img src="deltaend.gif" alt="End of change">takeover IP address.</strong> A floating address that is to be
|
||
|
|
associated with an application.</p>
|
||
|
|
|
||
|
|
<p><strong>Clustered hash table.</strong> Non-persistent data that can be
|
||
|
|
shared and replicated between cluster nodes using the <a href=
|
||
|
|
"clust4a1TOC.htm">Clustered Hash Table APIs</a>.</p>
|
||
|
|
|
||
|
|
<p><strong>Cluster resource group exit program.</strong> A program which
|
||
|
|
handles action codes that are passed to it.</p>
|
||
|
|
|
||
|
|
<p><strong>Cluster resource.</strong> A resource that is available on more than
|
||
|
|
one cluster node.</p>
|
||
|
|
|
||
|
|
<p><strong>Cluster resource group.</strong> A grouping of cluster resources.
|
||
|
|
The group describes a recovery domain and supplies the name of the cluster
|
||
|
|
resource group exit program that manages the movement of an access point.</p>
|
||
|
|
|
||
|
|
<p><strong>Device domain.</strong> A subset of nodes in a cluster grouped
|
||
|
|
together to share physical hardware resources or the logical resources
|
||
|
|
associated with the physical hardware.</p>
|
||
|
|
|
||
|
|
<p><strong>Partition.</strong> Happens when you lose contact between one or
|
||
|
|
more nodes in the cluster and a failure of lost nodes cannot be confirmed.</p>
|
||
|
|
|
||
|
|
<p><strong><img src="delta.gif" alt="Start of change">
|
||
|
|
Peer model.</strong> Cluster resource groups of this model define nodes
|
||
|
|
in the recovery domain with a specific role of either peer or replicate. The peer
|
||
|
|
nodes are available to be the access point for the cluster resource groupbut .<img src="deltaend.gif" alt="End of change"></p>
|
||
|
|
|
||
|
|
<p><strong><img src="delta.gif" alt="Start of change">
|
||
|
|
Primary-backup model.</strong> Cluster resource groups of this model define nodes
|
||
|
|
in the recovery domain with a specific role of either primary, backup or replicate.
|
||
|
|
The primary and backup nodes are available to be the access point for the cluster resource group.
|
||
|
|
<img src="deltaend.gif" alt="End of change"></p>
|
||
|
|
|
||
|
|
<p><strong>Recovery domain.</strong> A subset of nodes in a cluster grouped
|
||
|
|
together to provide availability for one or more resources. A domain represents
|
||
|
|
the nodes of the cluster where a cluster resource exists. See <a href=
|
||
|
|
"clust3a1TOC.htm">Cluster Resource Groups APIs</a> for more information.</p>
|
||
|
|
|
||
|
|
<p><strong>Resilient resource.</strong> Resources that are recoverable by
|
||
|
|
Cluster Resource Services. Three types of system resources that can be
|
||
|
|
resilient are (1) objects being replicated between nodes, (2) applications
|
||
|
|
using a
|
||
|
|
<img src="delta.gif" alt="Start of change">takeover
|
||
|
|
<img src="deltaend.gif" alt="End of change">IP address, which can be
|
||
|
|
switched from one node to another, and (3)
|
||
|
|
hardware devices which can be switched from one node to another.</p>
|
||
|
|
|
||
|
|
<p><strong>Server takeover IP address.</strong> A takeover IP address for
|
||
|
|
servers associated with the relational database name in the device description
|
||
|
|
for an auxiliary storage pool.</p>
|
||
|
|
|
||
|
|
<p><strong>Singleton cluster.</strong> A one node cluster or a cluster with
|
||
|
|
only one active node.</p>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<center>
|
||
|
|
<table cellpadding="2" cellspacing="2">
|
||
|
|
<tr align="center">
|
||
|
|
<td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href=
|
||
|
|
"clust1.htm">Cluster APIs</a> | <a href="aplist.htm">APIs by category</a></td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
</center>
|
||
|
|
</body>
|
||
|
|
</html>
|
||
|
|
|