CentOS cluster computing

Abbreviations and systems

Redhat Clustering daemons and systems

System	Meaning	Runs on
CCS	Cluster Configuration System	Each node
CLVM	Cluster Logical Volume Manager. Provides volume management to nodes.	Each node
CMAN	Cluster Manager	Each node
DLM	Distributed Lock Manager	Each node
fenced	Fence Daemon - The DLM Distributed Lock manager daemon	Each node
GFS	Global File System. Shared storage among nodes.	Each node
GNDB	Global Network Block Device. Low level storage access over Ethernet	GFS server
LVS	Linux Virtual Server, routing software to privide IP load balancing	On two or more Linux gateways
RHCS	RedHat Cluster Suite - Software components to build various types of Clusters

Red Hat Cluster Suite Introduction

Red Hat Cluster Suite (RHCS) is an integrated set of software components that can be deployed in a variety of configurations to suit your needs for performance, high-availability, load balancing, scalability, file sharing, and economy.

RHCS consists of the following major components

• Cluster infrastructure — Provides fundamental functions for nodes to work together as a cluster: configuration-file management, membership management, lock management, and fencing.
• High-availability Service Management — Provides failover of services from one cluster node to another in case a node becomes inoperative.
• Cluster administration tools — Configuration and management tools for setting up, configuring, and managing a Red Hat cluster. The tools are for use with the Cluster Chapter Infrastructure components, the High-availability and Service Management components, and storage.
• Linux Virtual Server (LVS) — Routing software that provides IP-Load-balancing. LVS runs in a pair of redundant servers that distributes client requests evenly to real servers that are behind the LVS servers.

Additional Cluster Components

You can supplement Red Hat Cluster Suite with the following components, which are part of an optional package (and not part of Red Hat Cluster Suite):

• Red Hat GFS (Global File System) — Provides a cluster file system for use with Red Hat Cluster Suite. GFS allows multiple nodes to share storage at a block level as if the storage were connected locally to each cluster node.
• Cluster Logical Volume Manager (CLVM) — Provides volume management of cluster storage.
• Global Network Block Device (GNBD) — An ancillary component of GFS that exports block-level storage to Ethernet. This is an economical way to make block-level storage available to Red Hat GFS.

Cluster management with Conga

Starting luci and ricci

Follow the instructions in chapter 3 - Configuring Red Hat Cluster With Conga - in RedHat 5.2 Cluster Administration manual. Follow the instructions in

notes

Services

• ricci
• luci
• cman
• rgmanager

utilities

• clustat Cluster Status

Files

• /etc/cluster/cluster.conf

hostnames give all the nodes hostnames in /etc/hosts or use dns

• node1.tekkom.dk
• node2.tekkom.dk
• ..

hostname node1.tekkom.dk
vi /etc/sysconfig/network
service network restart

example

[root@node1 ~]# clustat
Cluster Status for webcluster2 @ Thu Apr  2 10:43:02 2009
Member Status: Quorate

 Member Name                             ID   Status
 ------ ----                             ---- ------
 node1.tekkom.dk                             1 Online, Local
 node2.tekkom.dk                             2 Online
 node3.tekkom.dk                             3 Offline


[root@node1 ~]# cat /etc/cluster/cluster.conf
<?xml version="1.0"?>
<cluster alias="webcluster2" config_version="10" name="webcluster2">
        <fence_daemon clean_start="0" post_fail_delay="0" post_join_delay="3"/>
        <clusternodes>
                <clusternode name="node1.tekkom.dk" nodeid="1" votes="1">
                        <fence/>
                </clusternode>
                <clusternode name="node2.tekkom.dk" nodeid="2" votes="1">
                        <fence/>
                </clusternode>
                <clusternode name="node3.tekkom.dk" nodeid="3" votes="1">
                        <fence/>
                </clusternode>
        </clusternodes>
        <cman/>
        <fencedevices/>
        <rm>
                <failoverdomains/>
                <resources>
                        <apache config_file="conf/httpd.conf" name="Appache2" server_root="/etc/httpd" shutdown_wait="0"/>
                </resources>
        </rm>
</cluster>

Manuls

Clustering

• RedHat 5.2 Cluster Administration
• Redhat 5.2 Cluster Suite Overview
• RedHat 5.2 Deployment Guide
• Redhat 5.2 Using Device Mapper - Configuring and administration
• RedHat 5.2 GFS Global File System
• GNBD Global Network Block Device - Using with GFS
• SAN Survial Guide
• RedHat 5.2 Cluster LVM (Logical Volume Manager)

• FreeNAS Network Attached Storage solution

Backup technologies

• IBM Backup and recovery