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| author | Bruce Momjian <bruce@momjian.us> | 2007-11-08 19:16:30 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2007-11-08 19:16:30 +0000 |
| commit | 621e14dcb280be61d1a942ddb5e98dcc167b4813 (patch) | |
| tree | 317057452bf52bbe36f2855f79c7974e53516aaf | |
| parent | 5db1c58a1acf76355fc0e322347b393876f9b83b (diff) | |
| download | postgresql-621e14dcb280be61d1a942ddb5e98dcc167b4813.tar.gz postgresql-621e14dcb280be61d1a942ddb5e98dcc167b4813.zip | |
Add "High Availability, Load Balancing, and Replication Feature Matrix"
table to docs.
| -rw-r--r-- | doc/src/sgml/high-availability.sgml | 207 |
1 files changed, 166 insertions, 41 deletions
diff --git a/doc/src/sgml/high-availability.sgml b/doc/src/sgml/high-availability.sgml index 974da2c80a0..6bb6046af36 100644 --- a/doc/src/sgml/high-availability.sgml +++ b/doc/src/sgml/high-availability.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/high-availability.sgml,v 1.17 2007/11/04 19:23:24 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/high-availability.sgml,v 1.18 2007/11/08 19:16:30 momjian Exp $ --> <chapter id="high-availability"> <title>High Availability, Load Balancing, and Replication</title> @@ -92,16 +92,23 @@ </para> <para> - Shared hardware functionality is common in network storage - devices. Using a network file system is also possible, though - care must be taken that the file system has full POSIX behavior. - One significant limitation of this method is that if the shared - disk array fails or becomes corrupt, the primary and standby - servers are both nonfunctional. Another issue is that the - standby server should never access the shared storage while + Shared hardware functionality is common in network storage devices. + Using a network file system is also possible, though care must be + taken that the file system has full POSIX behavior (see <xref + linkend="creating-cluster-nfs">). One significant limitation of this + method is that if the shared disk array fails or becomes corrupt, the + primary and standby servers are both nonfunctional. Another issue is + that the standby server should never access the shared storage while the primary server is running. </para> + </listitem> + </varlistentry> + + <varlistentry> + <term>File System Replication</term> + <listitem> + <para> A modified version of shared hardware functionality is file system replication, where all changes to a file system are mirrored to a file @@ -125,7 +132,7 @@ protocol to make nodes agree on a serializable transactional order. </varlistentry> <varlistentry> - <term>Warm Standby Using Point-In-Time Recovery</term> + <term>Warm Standby Using Point-In-Time Recovery (<acronym>PITR</>)</term> <listitem> <para> @@ -191,6 +198,21 @@ protocol to make nodes agree on a serializable transactional order. </varlistentry> <varlistentry> + <term>Asynchronous Multi-Master Replication</term> + <listitem> + + <para> + For servers that are not regularly connected, like laptops or + remote servers, keeping data consistent among servers is a + challenge. Using asynchronous multi-master replication, each + server works independently, and periodically communicates with + the other servers to identify conflicting transactions. The + conflicts can be resolved by users or conflict resolution rules. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term>Synchronous Multi-Master Replication</term> <listitem> @@ -223,21 +245,6 @@ protocol to make nodes agree on a serializable transactional order. </varlistentry> <varlistentry> - <term>Asynchronous Multi-Master Replication</term> - <listitem> - - <para> - For servers that are not regularly connected, like laptops or - remote servers, keeping data consistent among servers is a - challenge. Using asynchronous multi-master replication, each - server works independently, and periodically communicates with - the other servers to identify conflicting transactions. The - conflicts can be resolved by users or conflict resolution rules. - </para> - </listitem> - </varlistentry> - - <varlistentry> <term>Data Partitioning</term> <listitem> @@ -254,23 +261,6 @@ protocol to make nodes agree on a serializable transactional order. </varlistentry> <varlistentry> - <term>Multi-Server Parallel Query Execution</term> - <listitem> - - <para> - Many of the above solutions allow multiple servers to handle - multiple queries, but none allow a single query to use multiple - servers to complete faster. This solution allows multiple - servers to work concurrently on a single query. This is usually - accomplished by splitting the data among servers and having - each server execute its part of the query and return results - to a central server where they are combined and returned to - the user. Pgpool-II has this capability. - </para> - </listitem> - </varlistentry> - - <varlistentry> <term>Commercial Solutions</term> <listitem> @@ -285,4 +275,139 @@ protocol to make nodes agree on a serializable transactional order. </variablelist> + <para> + The table below (<xref linkend="high-availability-matrix">) summarizes + the capabilities of the various solutions listed above. + </para> + + <table id="high-availability-matrix"> + <title>High Availability, Load Balancing, and Replication Feature Matrix</title> + <tgroup cols="9"> + <thead> + <row> + <entry>Feature</entry> + <entry>Shared Disk Failover</entry> + <entry>File System Replication</entry> + <entry>Warm Standby Using PITR</entry> + <entry>Master-Slave Replication</entry> + <entry>Statement-Based Replication Middleware</entry> + <entry>Asynchronous Multi-Master Replication</entry> + <entry>Synchronous Multi-Master Replication</entry> + <entry>Data Partitioning</entry> + </row> + </thead> + + <tbody> + + <row> + <entry>No special hardware required</entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + </row> + + <row> + <entry>Allows multiple master servers</entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center"></entry> + </row> + + <row> + <entry>No master server overhead</entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + </row> + + <row> + <entry>Master server never locks others</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center">•</entry> + </row> + + <row> + <entry>Master failure will never lose data</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center"></entry> + </row> + + <row> + <entry>Slaves accept read-only queries</entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + </row> + + <row> + <entry>Per-table granularity</entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + </row> + + <row> + <entry>No conflict resolution necessary</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + <entry align="center"></entry> + <entry align="center"></entry> + <entry align="center">•</entry> + <entry align="center">•</entry> + </row> + + </tbody> + </tgroup> + </table> + + <para> + Many of the above solutions allow multiple servers to handle multiple + queries, but none allow a single query to use multiple servers to + complete faster. Multi-server parallel query execution allows multiple + servers to work concurrently on a single query. This is usually + accomplished by splitting the data among servers and having each server + execute its part of the query and return results to a central server + where they are combined and returned to the user. Pgpool-II has this + capability. + </para> + </chapter> |