<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Error Handling</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.6.19 Documentation" HREF="index.html"><LINK REL="UP" TITLE="Server Configuration" HREF="runtime-config.html"><LINK REL="PREVIOUS" TITLE="Version and Platform Compatibility" HREF="runtime-config-compatible.html"><LINK REL="NEXT" TITLE="Preset Options" HREF="runtime-config-preset.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2020-09-02T07:27:19"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="4" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.6.19 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="Version and Platform Compatibility" HREF="runtime-config-compatible.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="runtime-config.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 19. Server Configuration</TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="Preset Options" HREF="runtime-config-preset.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="RUNTIME-CONFIG-ERROR-HANDLING" >19.14. Error Handling</A ></H1 ><P ></P ><DIV CLASS="VARIABLELIST" ><DL ><DT ><A NAME="GUC-EXIT-ON-ERROR" ></A ><TT CLASS="VARNAME" >exit_on_error</TT > (<TT CLASS="TYPE" >boolean</TT >) </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 ><A NAME="GUC-RESTART-AFTER-CRASH" ></A ><TT CLASS="VARNAME" >restart_after_crash</TT > (<TT CLASS="TYPE" >boolean</TT >) </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 ><A NAME="GUC-DATA-SYNC-RETRY" ></A ><TT CLASS="VARNAME" >data_sync_retry</TT > (<TT CLASS="TYPE" >boolean</TT >) </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 ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="runtime-config-compatible.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="runtime-config-preset.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Version and Platform Compatibility</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="runtime-config.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Preset Options</TD ></TR ></TABLE ></DIV ></BODY ></HTML >