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diff --git a/docs/programmer_reference/transapp_hotfail.html b/docs/programmer_reference/transapp_hotfail.html index 6d4143dd..512a91a3 100644 --- a/docs/programmer_reference/transapp_hotfail.html +++ b/docs/programmer_reference/transapp_hotfail.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> @@ -22,9 +22,7 @@ </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="transapp_recovery.html">Prev</a> </td> - <th width="60%" align="center">Chapter 11. - Berkeley DB Transactional Data Store Applications - </th> + <th width="60%" align="center">Chapter 11. Berkeley DB Transactional Data Store Applications </th> <td width="20%" align="right"> <a accesskey="n" href="transapp_journal.html">Next</a></td> </tr> </table> @@ -39,142 +37,150 @@ </div> </div> <p> - For some applications, it may be useful to periodically snapshot - the database environment for use as a hot failover should the - primary system fail. The following steps can be taken to keep a - backup environment in close synchrony with an active environment. - The active environment is entirely unaffected by these procedures, - and both read and write operations are allowed during all steps - described here. + For some applications, it may be useful to periodically + snapshot the database environment for use as a hot failover + should the primary system fail. The following steps can be + taken to keep a backup environment in close synchrony with an + active environment. The active environment is entirely + unaffected by these procedures, and both read and write + operations are allowed during all steps described here. </p> - <p> - The procedure described here is not compatible with the concurrent - use of the transactional bulk insert optimization (transactions - started with the <a href="../api_reference/C/txnbegin.html#txnbegin_DB_TXN_BULK" class="olink">DB_TXN_BULK</a> flag). After the bulk optimization - is used, the archive must be created again from scratch starting - with step 1. + <p> + The procedure described here is not compatible with the + concurrent use of the transactional bulk insert optimization + (transactions started with the <a href="../api_reference/C/txnbegin.html#txnbegin_DB_TXN_BULK" class="olink">DB_TXN_BULK</a> flag). After the + bulk optimization is used, the archive must be created again + from scratch starting with step 1. </p> <p> - The <a href="../api_reference/C/db_hotbackup.html" class="olink">db_hotbackup</a> utility is the preferred way to automate generating a hot - failover system. The first step is to run <a href="../api_reference/C/db_hotbackup.html" class="olink">db_hotbackup</a> utility without the - <span class="bold"><strong>-u</strong></span> flag. This will create hot - backup copy of the databases in your environment. After that point - periodically running the <a href="../api_reference/C/db_hotbackup.html" class="olink">db_hotbackup</a> utility with the - <span class="bold"><strong>-u</strong></span> flag will copy the new - log files and run recovery on the backup copy to bring it current - with the primary environment. + The <a href="../api_reference/C/db_hotbackup.html" class="olink">db_hotbackup</a> utility is the preferred way to automate + generating a hot failover system. The first step is to run + <a href="../api_reference/C/db_hotbackup.html" class="olink">db_hotbackup</a> utility without the <span class="bold"><strong>-u</strong></span> + flag. This will create hot backup copy of the databases in + your environment. After that point periodically running the + <a href="../api_reference/C/db_hotbackup.html" class="olink">db_hotbackup</a> utility with the <span class="bold"><strong>-u</strong></span> + flag will copy the new log files and run recovery on the + backup copy to bring it current with the primary environment. </p> - <p> - Note that you can also create your own hot backup solution using - the <a href="../api_reference/C/envbackup.html" class="olink">DB_ENV->backup()</a> or <a href="../api_reference/C/envdbbackup.html" class="olink">DB_ENV->dbbackup()</a> methods. + <p> + Note that you can also create your own hot backup solution + using the <a href="../api_reference/C/envbackup.html" class="olink">DB_ENV->backup()</a> or <a href="../api_reference/C/envdbbackup.html" class="olink">DB_ENV->dbbackup()</a> methods. </p> - <p> - To implement your own hot fail over system, the steps below can be - followed. However, care should be taken on non-UNIX based systems - when copying the database files to be sure that they are either - quiescent, or that either the <a href="../api_reference/C/envbackup.html" class="olink">DB_ENV->backup()</a> or <a href="../api_reference/C/db_copy.html" class="olink">db_copy()</a> routine is - used to ensure atomic reads of the database pages. + <p> + To implement your own hot fail over system, the steps below + can be followed. However, care should be taken on non-UNIX + based systems when copying the database files to be sure that + they are either quiescent, or that either the <a href="../api_reference/C/envbackup.html" class="olink">DB_ENV->backup()</a> or + <a href="../api_reference/C/db_copy.html" class="olink">db_copy()</a> routine is used to ensure atomic reads of the + database pages. </p> <div class="orderedlist"> <ol type="1"> <li> - <p> - Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-s</strong></span> option in the active environment - to identify all of the active environment's database files, and - copy them to the backup directory. + <p> + Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-s</strong></span> + option in the active environment to + identify all of the active environment's database + files, and copy them to the backup directory. </p> - <p> - If the database files are stored in a separate directory from - the other Berkeley DB files, it will be simpler (and much - faster!) to copy the directory itself instead of the individual - files (see <a href="../api_reference/C/envadd_data_dir.html" class="olink">DB_ENV->add_data_dir()</a> for additional information). + <p> + If the database files are stored in a separate + directory from the other Berkeley DB files, it will be + simpler (and much faster!) to copy the directory + itself instead of the individual files (see + <a href="../api_reference/C/envadd_data_dir.html" class="olink">DB_ENV->add_data_dir()</a> for additional information). </p> <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> <h3 class="title">Note</h3> <p> - If any of the database files did not have an open <a href="../api_reference/C/db.html" class="olink">DB</a> - handle during the lifetime of the current log files, - the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility will not list them in its output. This - is another reason it may be simpler to use a separate - database file directory and copy the entire directory - instead of archiving only the files listed by the + If any of the database files did not have an + open <a href="../api_reference/C/db.html" class="olink">DB</a> handle during the lifetime of the + current log files, the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility will not list + them in its output. This is another reason it may + be simpler to use a separate database file + directory and copy the entire directory instead of + archiving only the files listed by the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility. </p> </div> </li> <li> - Remove all existing log files from the backup directory. + Remove all existing log files from the backup + directory. </li> - <li> - Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-l</strong></span> - option in the active environment to identify all of the active - environment's log files, and copy them to the backup directory. + <li> + Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-l</strong></span> + option in the active environment to + identify all of the active environment's log files, and + copy them to the backup directory. </li> <li> - Run the <a href="../api_reference/C/db_recover.html" class="olink">db_recover</a> utility with the <span class="bold"><strong>-c</strong></span> - option in the backup directory to catastrophically recover the - copied environment. + Run the <a href="../api_reference/C/db_recover.html" class="olink">db_recover</a> utility with the <span class="bold"><strong>-c</strong></span> option + in the backup directory to catastrophically recover the copied environment. </li> </ol> </div> <p> - Steps 2, 3 and 4 may be repeated as often as you like. If Step 1 - (the initial copy of the database files) is repeated, then Steps 2, - 3 and 4 <span class="bold"><strong>must</strong></span> be performed at least - once in order to ensure a consistent database environment - snapshot. + Steps 2, 3 and 4 may be repeated as often as you like. If + Step 1 (the initial copy of the database files) is repeated, + then Steps 2, 3 and 4 <span class="bold"><strong>must</strong></span> be + performed at least once in order to ensure a consistent + database environment snapshot. </p> - <p> - These procedures must be integrated with your other archival - procedures, of course. If you are periodically removing log files - from your active environment, you must be sure to copy them to the - backup directory before removing them from the active directory. - Not copying a log file to the backup directory and subsequently - running recovery with it present may leave the backup snapshot of - the environment corrupted. A simple way to ensure this never - happens is to archive the log files in Step 2 as you remove them - from the backup directory, and move inactive log files from your - active environment into your backup directory (rather than copying - them), in Step 3. The following steps describe this procedure in - more detail: + <p> + These procedures must be integrated with your other + archival procedures, of course. If you are periodically + removing log files from your active environment, you must be + sure to copy them to the backup directory before removing them + from the active directory. Not copying a log file to the + backup directory and subsequently running recovery with it + present may leave the backup snapshot of the environment + corrupted. A simple way to ensure this never happens is to + archive the log files in Step 2 as you remove them from the + backup directory, and move inactive log files from your active + environment into your backup directory (rather than copying + them), in Step 3. The following steps describe this procedure + in more detail: </p> <div class="orderedlist"> <ol type="1"> <li> - Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-s</strong></span> - option in the active environment to identify all of the active - environment's database files, and copy them to the backup - directory. + Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-s</strong></span> option + in the active environment to identify all of the active environment's database files, + and copy them to the backup directory. </li> - <li> - Archive all existing log files from the backup directory, moving them - to a backup device such as CD-ROM, alternate disk, or tape. + <li> + Archive all existing log files from the backup + directory, moving them to a backup device such as CD-ROM, + alternate disk, or tape. </li> <li> - Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility (without any option) in the active environment - to identify all of the log files in the active environment that are - no longer in use, and <span class="bold"><strong>move</strong></span> them to - the backup directory. + Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility (without any option) in the + active environment to identify all of the log files in the + active environment that are no longer in use, and + <span class="bold"><strong>move</strong></span> them to the + backup directory. </li> - <li> - Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-l</strong></span> - option in the active environment to identify all of the remaining - log files in the active environment, and <span class="bold"><strong>copy</strong></span> the log files to the backup - directory. + <li> + Run the <a href="../api_reference/C/db_archive.html" class="olink">db_archive</a> utility with the <span class="bold"><strong>-l</strong></span> option + in the active environment to + identify all of the remaining log files in the active + environment, and <span class="bold"><strong>copy</strong></span> the + log files to the backup directory. </li> <li> - Run the <a href="../api_reference/C/db_recover.html" class="olink">db_recover</a> utility with the <span class="bold"><strong>-c</strong></span> - option in the backup directory to catastrophically recover the - copied environment. + Run the <a href="../api_reference/C/db_recover.html" class="olink">db_recover</a> utility with the <span class="bold"><strong>-c</strong></span> option + in the backup directory to + catastrophically recover the copied environment. </li> </ol> </div> - <p> - As before, steps 2, 3, 4 and 5 may be repeated as often as you - like. If Step 1 (the initial copy of the database files) is - repeated, then Steps 2 through 5 - <span class="bold"><strong>must</strong></span> be performed at least once in - order to ensure a consistent database environment snapshot. + <p> + As before, steps 2, 3, 4 and 5 may be repeated as often as + you like. If Step 1 (the initial copy of the database files) + is repeated, then Steps 2 through 5 <span class="bold"><strong>must</strong></span> be + performed at least once in order to + ensure a consistent database environment snapshot. </p> </div> <div class="navfooter"> |