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Diffstat (limited to 'docs/bdb-sql/sqlrep.html')
| -rw-r--r-- | docs/bdb-sql/sqlrep.html | 121 |
1 files changed, 112 insertions, 9 deletions
diff --git a/docs/bdb-sql/sqlrep.html b/docs/bdb-sql/sqlrep.html index 56822bdb..cbbad427 100644 --- a/docs/bdb-sql/sqlrep.html +++ b/docs/bdb-sql/sqlrep.html @@ -14,7 +14,7 @@ <body> <div xmlns="" class="navheader"> <div class="libver"> - <p>Library Version 11.2.5.3</p> + <p>Library Version 12.1.6.1</p> </div> <table width="100%" summary="Navigation header"> <tr> @@ -65,6 +65,11 @@ </dt> <dt> <span class="sect2"> + <a href="sqlrep.html#permmessage">Permanent Message Handling</a> + </span> + </dt> + <dt> + <span class="sect2"> <a href="sqlrep.html#twositerep">Two-Site Replication Groups</a> </span> </dt> @@ -84,6 +89,21 @@ </dt> <dt> <span class="sect2"> + <a href="reppragma.html#pragma_replication_ack_policy">PRAGMA replication_ack_policy</a> + </span> + </dt> + <dt> + <span class="sect2"> + <a href="reppragma.html#pragma_replication_ack_timeout">PRAGMA replication_ack_timeout</a> + </span> + </dt> + <dt> + <span class="sect2"> + <a href="reppragma.html#pragma_replication_get_master">PRAGMA replication_get_master</a> + </span> + </dt> + <dt> + <span class="sect2"> <a href="reppragma.html#pragma_replication_initial_master">PRAGMA replication_initial_master</a> </span> </dt> @@ -94,6 +114,21 @@ </dt> <dt> <span class="sect2"> + <a href="reppragma.html#pragma_replication_num_sites">PRAGMA replication_num_sites</a> + </span> + </dt> + <dt> + <span class="sect2"> + <a href="reppragma.html#pragma_replication_perm_failed">PRAGMA replication_perm_failed</a> + </span> + </dt> + <dt> + <span class="sect2"> + <a href="reppragma.html#pragma_replication_priority">PRAGMA replication_priority</a> + </span> + </dt> + <dt> + <span class="sect2"> <a href="reppragma.html#pragma_replication_remote_site">PRAGMA replication_remote_site</a> </span> </dt> @@ -104,6 +139,11 @@ </dt> <dt> <span class="sect2"> + <a href="reppragma.html#pragma_replication_site_status">PRAGMA replication_site_status</a> + </span> + </dt> + <dt> + <span class="sect2"> <a href="reppragma.html#pragma_replication_verbose_output">PRAGMA replication_verbose_output</a> </span> </dt> @@ -168,13 +208,6 @@ </li> </ul> </div> - <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> - <h3 class="title">Note</h3> - <p> - You cannot access a BDB SQL database using multiple - processes if you enable replication for that database. - </p> - </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> @@ -202,6 +235,11 @@ </dt> <dt> <span class="sect2"> + <a href="sqlrep.html#permmessage">Permanent Message Handling</a> + </span> + </dt> + <dt> + <span class="sect2"> <a href="sqlrep.html#twositerep">Two-Site Replication Groups</a> </span> </dt> @@ -335,7 +373,7 @@ </p> <p> For replicated BDB SQL applications, the durability - guarantee is extended because data modifications are + guarantee is enhanced because data modifications are also replicated to those environments that are participating in the replication group. This ensures higher data durability than non-replicated applications @@ -347,6 +385,71 @@ <div class="titlepage"> <div> <div> + <h3 class="title"><a id="permmessage"></a>Permanent Message Handling</h3> + </div> + </div> + </div> + <p> + Permanent messages are created by replication masters + as a part of a transactional commit operation. When a + replica receives a message that is marked as permanent, + it knows that the message affects transactional + integrity. Receipt of a permanent message means that + the replica must send a message acknowledgment back to + the master server because the master + <span class="emphasis"><em>might be</em></span> waiting for the + acknowledgment before it considers the transaction + commit to be complete. + </p> + <p> + Whether the master is actually waiting for message + acknowledgement depends on the acknowledgement policy + in effect for the replication group. Policies can range + from <code class="literal">NONE</code> (the master will not wait + for any acknowledgements before completing the + transaction) to <code class="literal">ALL</code> (the master will + wait for acknowledgements from all replicas before + completing the transaction). + </p> + <p> + Acknowledgements are only sent back to the master once + the replica has completed applying the message to its + local environment. Therefore, the stronger your + acknowledgement policy, the stronger you durability + guarantee. On the other hand, the stronger your + acknowledgement policy, the slower your application's + write throughput will be. + </p> + <p> + In addition to setting an acknowledgement policy, you + can also set an acknowledgment timeout. This time limit + is set in microseconds and it represents the length of + time the master will wait to satisfy its + acknowledgement policy for each transaction commit. If + this timeout value is not met, the transaction is still + committed locally to the master, but is not yet + considered durable across the replication group. Your + code should take whatever actions are appropriate for + that transaction. If enough other sites are available + to meet the acknowledgement policy, the transaction + will become durable after more time has passed. + </p> + <p> + You set acknowledgement policies and acknowledgement timeouts + using PRAGMAs. See + <a class="xref" href="reppragma.html#pragma_replication_ack_policy" title="PRAGMA replication_ack_policy">PRAGMA replication_ack_policy</a> + and + <a class="xref" href="reppragma.html#pragma_replication_ack_timeout" title="PRAGMA replication_ack_timeout">PRAGMA replication_ack_timeout</a>. + In addition, you can examine how frequently your + transactions do not achieve durability within the + acknowledgement timeout by using + <a class="xref" href="reppragma.html#pragma_replication_perm_failed" title="PRAGMA replication_perm_failed">PRAGMA replication_perm_failed</a>. + </p> + </div> + <div class="sect2" lang="en" xml:lang="en"> + <div class="titlepage"> + <div> + <div> <h3 class="title"><a id="twositerep"></a>Two-Site Replication Groups</h3> </div> </div> |