Reviewed-by: Angus Salkeld <asalkeld@xxxxxxxxxx> On 13/02/12 14:06 -0700, Steven Dake wrote:
Move forward 5 years on our main man page ;) Signed-off-by: Steven Dake <sdake@xxxxxxxxxx> --- man/corosync_overview.8 | 127 ++++++++++------------------------------------- 1 files changed, 26 insertions(+), 101 deletions(-) diff --git a/man/corosync_overview.8 b/man/corosync_overview.8 index 6d95fe9..fb3766f 100644 --- a/man/corosync_overview.8 +++ b/man/corosync_overview.8 @@ -32,19 +32,13 @@ .\" * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF .\" * THE POSSIBILITY OF SUCH DAMAGE. .\" */ -.TH COROSYNC_OVERVIEW 8 2006-05-10 "corosync Man Page" "Corosync Cluster Engine Programmer's Manual" +.TH COROSYNC_OVERVIEW 8 2012-02-13 "corosync Man Page" "Corosync Cluster Engine Programmer's Manual" .SH NAME corosync_overview \- Corosync overview .SH OVERVIEW -The corosync project is a project to implement a production quality "Revised BSD" -licensed implementation of the most recent SA Forum's Application Interface -Specification. The Application Interface Specification is a software API and -policies which are used to develop applications that maintain service during -faults. The API consists of Availability Management Framework (AMF) which -provides application failover, Cluster Membership (CLM), Checkpointing (CKPT), -Eventing (EVT), Messaging (MSG), and Distributed Locking (DLOCK). - -Currently Messaging is unimplemented. +The corosync project's purpose is to implement and support a production quality +Revised BSD licensed implementation of a high performance low overhead high +availability development toolkit. Faults occur for various reasons: .PP @@ -58,33 +52,18 @@ Faults occur for various reasons: The major focus of high availability in the past has been to mask hardware faults. Faults in other components of the system have gone unsolved until -AIS. AIS can mask many types of faults in applications, middleware, -operating systems, or even hardware by providing a simple framework -for allowing developers to create redundant applications. These redundant -applications can be distributed over multiple nodes such that if any one -node faults, another node can recover. - -Application programmers develop applications to periodically record their -state using the checkpointing service. When an active application fails, -a standby application recovers the state of the application. This -technique, called stateful application failover, provides the fundamental -difference between corosync and other systems that have come before it. -With stateful application failover, the end-application user doesn't -have to reload the application or redial a telephone. The full state -is recorded, so the end-application user sees no interruption in service. - -Because programmers can now distribute applications across multiple -processes or nodes, a mechanism must exist for them to communicate. -This mechanism is provided by two services. The event service provides -a publish/subscribe model for events. The messaging service provides -end to end messaging. Finally a mechanism to synchronize access is -provided by the distributed lock service. - -The corosync project also provides a group messaging toolkit called EVS. -The EVS service implements a messaging model known as Extended Virtual -Synchrony. This model allows one sender to transmit to many receivers. -Certain guarantees are provided for message and membership delivery -which make virtual synchrony ideal for developing distributed applications. +Corosync. Corosync is designed for applications to replicate their state to +up to 16 processors. The processors all contain a replica of the application +state. + +The corosync project provides two group message APIs called CPG and EVS. +The project developers recommend CPG be used for most applications. The CPG +service implmeents a closed group messaging model presenting extended virtual +synchrony guarantees. + +To manage conditions where the process executing the CPG application exchange +fails, we provide the Simple Availability Manager (sam) to provide simple +application restart. .SH QUICKSTART The corosync executive must be configured. In the directory conf in the @@ -130,44 +109,13 @@ Finally run the corosync executive. If corosync is packaged from a distro, it may be set to start on system start. It may also be turned off by default in which case the init script for corosync must be enabled. -After running aisexec, a list of all processors IP addresses running the corosync -executive and configured on the same multicast address will appear. If they -don't appear, there may be a problem with multicast in the distro or hardware. -If this happens, participation in the corosync mailing list may help solve the -problem. The email address is openais@xxxxxxxxxxxxxx. - .SH USING LIBRARIES -The corosync AIS libraries have header files which must be included in the +The corosync libraries have header files which must be included in the developer's application. Once the header file is included, the developer can -reference the AIS interfaces. +reference the corosync interfaces. The corosync project recommends to distros to place include files in -/usr/include/corosync. The following include lines must be added to -the application to use each of the following services: - -#include <corosync/saClm.h> For the Cluster Membership B.01.01 service. -.PP -#include <corosync/saCkpt.h> For the Checkpointing B.01.01 service. -.PP -#include <corosync/saEvt.h> For the Eventing B.01.01 service. -.PP -#include <corosync/ais_amf.h> For the AMF A.01.01 service. -.PP - -The corosync project recommends to distros to place library files in -/usr/lib. The following link lines must be added to the LDFLAGS section -of the makefile. - --lsaClm For the Cluster Membership B.01.01 service -.PP --lsaCkpt For the Checkpointing B.01.01 service -.PP --lsaEvt For the Eventing B.01.01 service -.PP --lsaAmf For the AMF A.01.01 service -.PP --lais Specify this to get access to all AIS libraries without specifying -each library individually. +/usr/include/corosync. .SH IPv6 The corosync project supports both IPv4 and IPv6 network addresses. The entire @@ -190,9 +138,9 @@ which will cause significant problems. Make sure a route is available for IPv6 traffic. .SH ARCHITECTURE -The AIS libraries are a thin IPC interface to the corosync executive. The -corosync executive provides services for the SA Forum AIS libraries as well -as the EVS and CPG libraries. +The corosync libraries are a thin IPC interface to the corosync executive. The +corosync executive implements the functionality of the corosync APIs for +distributed coming. The corosync executive uses the Totem extended virtual synchrony protocol. The advantage to the end user is excellent performance characteristics and a proven @@ -210,21 +158,6 @@ This specifies the fully qualified path to the corosync configuration file. The default is /etc/corosync/corosync.conf. .TP -COROSYNC_AMF_CONFIG_FILE -This specifies the fully qualified path to the corosync Availability Management -Framework configuration file. - -The default is /etc/corosync/amf.conf. - -.TP -COROSYNC_DEFAULT_CONFIG_IFACE -This specifies the LCRSO that is used to parse the configuration file. This -allows other configuration file parsers to be implemented within the system. - -The default is to use the default corosync configuration file parser which -parses the format specified in corosync.conf (5). - -.TP COROSYNC_TOTEM_AUTHKEY_FILE This specifies the fully qualified path to the shared key used to authenticate and encrypt data used within the Totem protocol. @@ -252,21 +185,13 @@ compromised to allow the long-term capture of transmitted data. For security reasons, the corosync executive binary should NEVER be setuid or setgid in the filesystem. -.PP -.SH SAFTEST COMPLIANCE -The corosync libraries are now nearly compliant with every aspect of the SA -Forum's AIS specification. The AMF service, however, is not compliant with the -B.01.01 specification. The remaining services pass most of the tests of the -saftest suite against the B.01.01 specification. - .SH BUGS -The messaging service is partially implemented and not suitable for deployment. -The distributed locking service is buggy and not suitable for deployment. -The Availability Management Framework is under development and not suitable for -deployment.. +None that are known. .SH "SEE ALSO" .BR corosync.conf (5), .BR corosync-keygen (8), -.BR evs_overview (8) +.BR evs_overview (8), +.BR cpg_overview (8), +.BR sam_overview (8) .PP -- 1.7.7.6 _______________________________________________ discuss mailing list discuss@xxxxxxxxxxxx http://lists.corosync.org/mailman/listinfo/discuss
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