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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >pg_receivexlog</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 9.2.24 Documentation" HREF="index.html"><LINK REL="UP" TITLE="PostgreSQL Client Applications" HREF="reference-client.html"><LINK REL="PREVIOUS" TITLE="pg_dumpall" HREF="app-pg-dumpall.html"><LINK REL="NEXT" TITLE="pg_restore" HREF="app-pgrestore.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="2017-11-06T22:43:11"></HEAD ><BODY CLASS="REFENTRY" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.2.24 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="pg_dumpall" HREF="app-pg-dumpall.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="reference-client.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="pg_restore" HREF="app-pgrestore.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="APP-PGRECEIVEXLOG" ></A >pg_receivexlog</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN83196" ></A ><H2 >Name</H2 >pg_receivexlog -- streams transaction logs from a <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > cluster</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN83202" ></A ><H2 >Synopsis</H2 ><P ><TT CLASS="COMMAND" >pg_receivexlog</TT > [<TT CLASS="REPLACEABLE" ><I >option</I ></TT >...]</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN83207" ></A ><H2 > Description </H2 ><P > <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > is used to stream transaction log from a running <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > cluster. The transaction log is streamed using the streaming replication protocol, and is written to a local directory of files. This directory can be used as the archive location for doing a restore using point-in-time recovery (see <A HREF="continuous-archiving.html" >Section 24.3</A >). </P ><P > <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > streams the transaction log in real time as it's being generated on the server, and does not wait for segments to complete like <A HREF="runtime-config-wal.html#GUC-ARCHIVE-COMMAND" >archive_command</A > does. For this reason, it is not necessary to set <A HREF="runtime-config-wal.html#GUC-ARCHIVE-TIMEOUT" >archive_timeout</A > when using <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN >. </P ><P > The transaction log is streamed over a regular <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > connection, and uses the replication protocol. The connection must be made with a superuser or a user having <TT CLASS="LITERAL" >REPLICATION</TT > permissions (see <A HREF="role-attributes.html" >Section 20.2</A >), and <TT CLASS="FILENAME" >pg_hba.conf</TT > must explicitly permit the replication connection. The server must also be configured with <A HREF="runtime-config-replication.html#GUC-MAX-WAL-SENDERS" >max_wal_senders</A > set high enough to leave at least one session available for the stream. </P ><P > If the connection is lost, or if it cannot be initially established, with a non-fatal error, <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > will retry the connection indefinitely, and reestablish streaming as soon as possible. To avoid this behavior, use the <TT CLASS="LITERAL" >-n</TT > parameter. </P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN83227" ></A ><H2 >Options</H2 ><P > The following command-line options control the location and format of the output. <P ></P ></P><DIV CLASS="VARIABLELIST" ><DL ><DT ><TT CLASS="OPTION" >-D <TT CLASS="REPLACEABLE" ><I >directory</I ></TT ></TT ><BR><TT CLASS="OPTION" >--directory=<TT CLASS="REPLACEABLE" ><I >directory</I ></TT ></TT ></DT ><DD ><P > Directory to write the output to. </P ><P > This parameter is required. </P ></DD ></DL ></DIV ><P> </P ><P > The following command-line options control the running of the program. <P ></P ></P><DIV CLASS="VARIABLELIST" ><DL ><DT ><TT CLASS="OPTION" >-n</TT ><BR><TT CLASS="OPTION" >--no-loop</TT ></DT ><DD ><P > Don't loop on connection errors. Instead, exit right away with an error. </P ></DD ><DT ><TT CLASS="OPTION" >-v</TT ><BR><TT CLASS="OPTION" >--verbose</TT ></DT ><DD ><P > Enables verbose mode. </P ></DD ></DL ></DIV ><P> </P ><P > The following command-line options control the database connection parameters. <P ></P ></P><DIV CLASS="VARIABLELIST" ><DL ><DT ><TT CLASS="OPTION" >-h <TT CLASS="REPLACEABLE" ><I >host</I ></TT ></TT ><BR><TT CLASS="OPTION" >--host=<TT CLASS="REPLACEABLE" ><I >host</I ></TT ></TT ></DT ><DD ><P > Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix domain socket. The default is taken from the <TT CLASS="ENVAR" >PGHOST</TT > environment variable, if set, else a Unix domain socket connection is attempted. </P ></DD ><DT ><TT CLASS="OPTION" >-p <TT CLASS="REPLACEABLE" ><I >port</I ></TT ></TT ><BR><TT CLASS="OPTION" >--port=<TT CLASS="REPLACEABLE" ><I >port</I ></TT ></TT ></DT ><DD ><P > Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections. Defaults to the <TT CLASS="ENVAR" >PGPORT</TT > environment variable, if set, or a compiled-in default. </P ></DD ><DT ><TT CLASS="OPTION" >-s <TT CLASS="REPLACEABLE" ><I >interval</I ></TT ></TT ><BR><TT CLASS="OPTION" >--status-interval=<TT CLASS="REPLACEABLE" ><I >interval</I ></TT ></TT ></DT ><DD ><P > Specifies the number of seconds between status packets sent back to the server. This is required if replication timeout is configured on the server, and allows for easier monitoring. A value of zero disables the status updates completely. The default value is 10 seconds. </P ></DD ><DT ><TT CLASS="OPTION" >-U <TT CLASS="REPLACEABLE" ><I >username</I ></TT ></TT ><BR><TT CLASS="OPTION" >--username=<TT CLASS="REPLACEABLE" ><I >username</I ></TT ></TT ></DT ><DD ><P > User name to connect as. </P ></DD ><DT ><TT CLASS="OPTION" >-w</TT ><BR><TT CLASS="OPTION" >--no-password</TT ></DT ><DD ><P > Never issue a password prompt. If the server requires password authentication and a password is not available by other means such as a <TT CLASS="FILENAME" >.pgpass</TT > file, the connection attempt will fail. This option can be useful in batch jobs and scripts where no user is present to enter a password. </P ></DD ><DT ><TT CLASS="OPTION" >-W</TT ><BR><TT CLASS="OPTION" >--password</TT ></DT ><DD ><P > Force <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > to prompt for a password before connecting to a database. </P ><P > This option is never essential, since <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > will automatically prompt for a password if the server demands password authentication. However, <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > will waste a connection attempt finding out that the server wants a password. In some cases it is worth typing <TT CLASS="OPTION" >-W</TT > to avoid the extra connection attempt. </P ></DD ></DL ></DIV ><P> </P ><P > Other options are also available: <P ></P ></P><DIV CLASS="VARIABLELIST" ><DL ><DT ><TT CLASS="OPTION" >-V</TT ><BR><TT CLASS="OPTION" >--version</TT ></DT ><DD ><P > Print the <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > version and exit. </P ></DD ><DT ><TT CLASS="OPTION" >-?</TT ><BR><TT CLASS="OPTION" >--help</TT ></DT ><DD ><P > Show help about <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > command line arguments, and exit. </P ></DD ></DL ></DIV ><P> </P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN83335" ></A ><H2 >Environment</H2 ><P > This utility, like most other <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > utilities, uses the environment variables supported by <SPAN CLASS="APPLICATION" >libpq</SPAN > (see <A HREF="libpq-envars.html" >Section 31.14</A >). </P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN83341" ></A ><H2 >Notes</H2 ><P > When using <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > instead of <A HREF="runtime-config-wal.html#GUC-ARCHIVE-COMMAND" >archive_command</A >, the server will continue to recycle transaction log files even if the backups are not properly archived, since there is no command that fails. This can be worked around by having an <A HREF="runtime-config-wal.html#GUC-ARCHIVE-COMMAND" >archive_command</A > that fails when the file has not been properly archived yet, for example: </P><PRE CLASS="PROGRAMLISTING" >archive_command = 'sleep 5 && test -f /mnt/server/archivedir/%f'</PRE ><P> The initial timeout is necessary because <SPAN CLASS="APPLICATION" >pg_receivexlog</SPAN > works using asynchronous replication and can therefore be slightly behind the master. </P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN83349" ></A ><H2 >Examples</H2 ><P > To stream the transaction log from the server at <TT CLASS="LITERAL" >mydbserver</TT > and store it in the local directory <TT CLASS="FILENAME" >/usr/local/pgsql/archive</TT >: </P><PRE CLASS="SCREEN" ><SAMP CLASS="PROMPT" >$</SAMP > <KBD CLASS="USERINPUT" >pg_receivexlog -h mydbserver -D /usr/local/pgsql/archive</KBD ></PRE ><P></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN83357" ></A ><H2 >See Also</H2 ><A HREF="app-pgbasebackup.html" >pg_basebackup</A ></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="app-pg-dumpall.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="app-pgrestore.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><SPAN CLASS="APPLICATION" >pg_dumpall</SPAN ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="reference-client.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >pg_restore</TD ></TR ></TABLE ></DIV ></BODY ></HTML >