High Availability Cluster Multiprocessing
Encyclopedia
HACMP is IBM's solution for high-availability cluster
s on the AIX
Unix
and Linux
for IBM System p
platforms and stands for High Availability Cluster Multiprocessing. IBM's HACMP product was first shipped in 1991 and is now in its 20th release - PowerHA SystemMirror for AIX 7.1
In the current release, PowerHA can run on up to 16 computers or nodes, each of which is either actively running an application (active) or waiting to take over should another node fail (passive). Data on file system
s can be shared between systems in the cluster.
PowerHA relies heavily on IBM's Reliable Scalable Cluster Technology
(RSCT). PowerHA is an RSCT aware client. RSCT is distributed with AIX. RSCT includes a daemon called group services that coordinates the response to events of interest to the cluster (for example, an interface or a node fails, or an administrator makes a change to the cluster configuration). Up until PowerHA V6.1, RSCT also monitored cluster nodes, networks and network adapters for failures using the topology services daemon (topsvcs). In the current release (V7.1), RSCT provides coordinate response between nodes, but monitoring and communication are provided by the Cluster Aware AIX (CAA) infrastructure.
The 7.1 release of PowerHA relies heavily on CAA, a clustering infrastructure built into the operating system and exploited by RSCT and PowerHA. CAA provides the monitoring and communication infrastructure for PowerHA and other clustering solutions on AIX, as well as cluster-wide event notification using the Autonomic Health Advisor File System (AHAFS) and cluster-aware AIX commands with clcmd. CAA replaces the function provided by Topology Services (topsvcs) in RSCT in previous releases of PowerHA/HACMP http://publib.boulder.ibm.com/infocenter/aix/v7r1/index.jsp?topic=/com.ibm.aix.clusteraware/claware_main.htm.
High-availability cluster
High-availability clusters are groups of computers that support server applications that can be reliably utilized with a minimum of down-time. They operate by harnessing redundant computers in groups or clusters that provide continued service when system components fail...
s on the AIX
AIX operating system
AIX AIX AIX (Advanced Interactive eXecutive, pronounced "a i ex" is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms...
Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
and Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
for IBM System p
IBM System p
The System p, formerly known as RS/6000, was IBM's RISC/UNIX-based server and workstation product line.In April 2008, IBM announced a rebranding of the System p and its unification with the System i platform. The resulting product line is called IBM Power Systems.-History:It was originally a line...
platforms and stands for High Availability Cluster Multiprocessing. IBM's HACMP product was first shipped in 1991 and is now in its 20th release - PowerHA SystemMirror for AIX 7.1
In the current release, PowerHA can run on up to 16 computers or nodes, each of which is either actively running an application (active) or waiting to take over should another node fail (passive). Data on file system
File system
A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...
s can be shared between systems in the cluster.
PowerHA relies heavily on IBM's Reliable Scalable Cluster Technology
IBM RSCT
IBM Reliable Scalable Cluster Technology is a set of software components that together provide a comprehensive clustering environment for AIX and Linux. RSCT is the infrastructure used by a variety of IBM products to provide clusters with improved system availability, scalability, and ease of use...
(RSCT). PowerHA is an RSCT aware client. RSCT is distributed with AIX. RSCT includes a daemon called group services that coordinates the response to events of interest to the cluster (for example, an interface or a node fails, or an administrator makes a change to the cluster configuration). Up until PowerHA V6.1, RSCT also monitored cluster nodes, networks and network adapters for failures using the topology services daemon (topsvcs). In the current release (V7.1), RSCT provides coordinate response between nodes, but monitoring and communication are provided by the Cluster Aware AIX (CAA) infrastructure.
The 7.1 release of PowerHA relies heavily on CAA, a clustering infrastructure built into the operating system and exploited by RSCT and PowerHA. CAA provides the monitoring and communication infrastructure for PowerHA and other clustering solutions on AIX, as well as cluster-wide event notification using the Autonomic Health Advisor File System (AHAFS) and cluster-aware AIX commands with clcmd. CAA replaces the function provided by Topology Services (topsvcs) in RSCT in previous releases of PowerHA/HACMP http://publib.boulder.ibm.com/infocenter/aix/v7r1/index.jsp?topic=/com.ibm.aix.clusteraware/claware_main.htm.
Recent Versions
- PowerHA 7.1 was released in 2010 and uses the Cluster Aware AIX (CAA) infrastructure available in AIX V6.1 TL 6 and AIX 7.1 http://www-03.ibm.com/systems/power/software/availability/aix/index.html
- PowerHA 6.1, Rebranded again to IBM PowerHA SystemMirror for AIX, GA Oct 27 2009, http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&appname=GPA&htmlfid=897/ENUS609-077
- Now in Standard and Enterprise Editions
- EMC SRDF support
- GLVM 2-site Configuration Wizard
- Improvements to SMIT panels and File Collections
- IPv6 support
- HACMP 5.5, Rebranded to IBM PowerHA, GA Nov 2008, http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&appname=GPA&htmlfid=897/ENUS208-313
- Asynchronous replication support
- Updated support for DLPAR/CUOD to include support for IBM POWER5 and POWER6 processors
- Support for LPAR mobility to relocate critical applications
- PowerHA/XD PPRC support of Global Mirror when used with SAN Volume Controller
- Function to allow PowerHA/XD PPRC to support multiple storage subsystems at each site
- Better integration with the AIX operating system by avoiding modifications to the TCP/IP bringing up process
- HACMP 5.4.1, Nov 2007, announcement
- AIX Workload Partitions support (WPAR)
- New GLVM monitoring
- NFSv4 support improvements
- HACMP 5.4, July 2006, announcement
- Web-based GUI
- Nondisruptive HACMP cluster startup, upgrades, and maintenance
- HACMP 5.3, August 2005
- HACMP 5.2, July 2004
- HACMP 5.1, July 2003
- HACMP 4.5, July 2002
- HACMP 4.4, June 2000
- HACMP 4.3
- HAMCP 4.2
- Adds Cluster Single Point of Control (CSPOC) feature
- Dynamic Reconfig