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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>19.14. Error Handling</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="runtime-config-compatible.html" title="19.13. Version and Platform Compatibility" /><link rel="next" href="runtime-config-preset.html" title="19.15. Preset Options" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">19.14. Error Handling</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="runtime-config-compatible.html" title="19.13. Version and Platform Compatibility">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="runtime-config.html" title="Chapter 19. Server Configuration">Up</a></td><th width="60%" align="center">Chapter 19. Server Configuration</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="runtime-config-preset.html" title="19.15. Preset Options">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RUNTIME-CONFIG-ERROR-HANDLING"><div class="titlepage"><div><div><h2 class="title" style="clear: both">19.14. Error Handling</h2></div></div></div><div class="variablelist"><dl class="variablelist"><dt id="GUC-EXIT-ON-ERROR"><span class="term"><code class="varname">exit_on_error</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.17.2.1.1.3" class="indexterm"></a>
</span></dt><dd><p>
If true, any error will terminate the current session. By default,
this is set to false, so that only FATAL errors will terminate the
session.
</p></dd><dt id="GUC-RESTART-AFTER-CRASH"><span class="term"><code class="varname">restart_after_crash</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.17.2.2.1.3" class="indexterm"></a>
</span></dt><dd><p>
When set to true, which is the default, <span class="productname">PostgreSQL</span>
will automatically reinitialize after a backend crash. Leaving this
value set to true is normally the best way to maximize the availability
of the database. However, in some circumstances, such as when
<span class="productname">PostgreSQL</span> is being invoked by clusterware, it may be
useful to disable the restart so that the clusterware can gain
control and take any actions it deems appropriate.
</p></dd><dt id="GUC-DATA-SYNC-RETRY"><span class="term"><code class="varname">data_sync_retry</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.17.2.3.1.3" class="indexterm"></a>
</span></dt><dd><p>
When set to false, which is the default, <span class="productname">PostgreSQL</span>
will raise a PANIC-level error on failure to flush modified data files
to the filesystem. This causes the database server to crash. This
parameter can only be set at server start.
</p><p>
On some operating systems, the status of data in the kernel's page
cache is unknown after a write-back failure. In some cases it might
have been entirely forgotten, making it unsafe to retry; the second
attempt may be reported as successful, when in fact the data has been
lost. In these circumstances, the only way to avoid data loss is to
recover from the WAL after any failure is reported, preferably
after investigating the root cause of the failure and replacing any
faulty hardware.
</p><p>
If set to true, <span class="productname">PostgreSQL</span> will instead
report an error but continue to run so that the data flushing
operation can be retried in a later checkpoint. Only set it to true
after investigating the operating system's treatment of buffered data
in case of write-back failure.
</p></dd></dl></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="runtime-config-compatible.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="runtime-config.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="runtime-config-preset.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">19.13. Version and Platform Compatibility </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 19.15. Preset Options</td></tr></table></div></body></html>
