Tom Lane wrote:
> Oliver Jowett <[EMAIL PROTECTED]> writes:
>
>>Tom Lane wrote:
>>
>>>I'm not convinced that Postgres ought to provide
>>>a way to second-guess the TCP stack ...
>
>
>>Would you be ok with a patch that allowed configuration of the
>>TCP_KEEPCNT / TCP_KEEPIDLE / TCP_KEEPINTVL socket options on backend
>>sockets?
>
>
> [ shrug... ] As long as it doesn't fail to build on platforms that
> don't offer those options, I couldn't complain too hard. But do we
> really need all that?
Here's a patch that adds four new GUCs:
tcp_keepalives (defaults to on, controls SO_KEEPALIVE)
tcp_keepalives_idle (controls TCP_KEEPIDLE)
tcp_keepalives_interval (controls TCP_KEEPINTVL)
tcp_keepalives_count (controls TCP_KEEPCNT)
They're ignored for AF_UNIX connections and when running standalone.
tcp_keepalives_* treat 0 as "use system default". If the underlying OS
doesn't provide the TCP_KEEP* socket options, the GUCs are present but
reject any value other than 0.
SHOW reflects the currently-in-use value or 0 if not applicable or not
known. i.e. if you set it to 0 and you have the socket options
available, SHOW will show the result of getsockopt() which is non-zero.
A default install on my Linux system produces:
template1=# show all;
name | setting
--------------------------------+----------------------------------------------
[...]
tcp_keepalives | on
tcp_keepalives_count | 9
tcp_keepalives_idle | 7200
tcp_keepalives_interval | 75
[...]
I haven't had a chance to check it builds on other systems or to test
that this handles actual network failures nicely yet.
-O
Index: doc/src/sgml/runtime.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/runtime.sgml,v
retrieving revision 1.315
diff -c -r1.315 runtime.sgml
*** doc/src/sgml/runtime.sgml 23 Apr 2005 03:27:40 -0000 1.315
--- doc/src/sgml/runtime.sgml 3 May 2005 01:44:02 -0000
***************
*** 889,894 ****
--- 889,961 ----
</listitem>
</varlistentry>
+ <varlistentry id="guc-tcp-keepalives" xreflabel="tcp_keepalives">
+ <term><varname>tcp_keepalives</varname> (<type>boolean</type>)</term>
+ <indexterm>
+ <primary><varname>tcp_keepalives</> configuration parameter</primary>
+ </indexterm>
+ <listitem>
+ <para>
+ Controls the use of TCP keepalives on client connections. When
enabled,
+ idle connections will be periodically probed to check that the client
+ is still present. If sufficient probes are lost, the connection will
+ be broken. This option is ignored for connections made via a
+ Unix-domain socket.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="guc-tcp-keepalives-idle"
xreflabel="tcp_keepalives_idle">
+ <term><varname>tcp_keepalives_idle</varname>
(<type>integer</type>)</term>
+ <indexterm>
+ <primary><varname>tcp_keepalives_idle</> configuration
parameter</primary>
+ </indexterm>
+ <listitem>
+ <para>
+ On systems that support the TCP_KEEPIDLE socket option, specifies the
+ number of seconds between sending keepalives on an otherwise idle
+ connection. A value of 0 uses the system default. If TCP_KEEPIDLE is
+ not supported, this parameter must be 0. This option is ignored for
+ connections made via a Unix-domain socket, and will have no effect
+ unless the <varname>tcp_keepalives</varname> option is enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="guc-tcp-keepalives-interval"
xreflabel="tcp_keepalives_interval">
+ <term><varname>tcp_keepalives_interval</varname>
(<type>integer</type>)</term>
+ <indexterm>
+ <primary><varname>tcp_keepalives_interval</> configuration
parameter</primary>
+ </indexterm>
+ <listitem>
+ <para>
+ On systems that support the TCP_KEEPINTVL socket option, specifies how
+ long, in seconds, to wait for a response to a keepalive before
+ retransmitting. A value of 0 uses the system default. If TCP_KEEPINTVL
+ is not supported, this parameter must be 0. This option is ignored
+ for connections made via a Unix-domain socket, and will have no effect
+ unless the <varname>tcp_keepalives</varname> option is enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="guc-tcp-keepalives-count"
xreflabel="tcp_keepalives_count">
+ <term><varname>tcp_keepalives_count</varname>
(<type>integer</type>)</term>
+ <indexterm>
+ <primary><varname>tcp_keepalives_count</> configuration
parameter</primary>
+ </indexterm>
+ <listitem>
+ <para>
+ On systems that support the TCP_KEEPCNT socket option, specifies how
+ many keepalives may be lost before the connection is considered dead.
+ A value of 0 uses the system default. If TCP_KEEPINTVL is not
+ supported, this parameter must be 0. This option is ignored for
+ connections made via a Unix-domain socket, and will have no effect
+ unless the <varname>tcp_keepalives</varname> option is enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect3>
<sect3 id="runtime-config-connection-security">
Index: src/backend/libpq/pqcomm.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/libpq/pqcomm.c,v
retrieving revision 1.176
diff -c -r1.176 pqcomm.c
*** src/backend/libpq/pqcomm.c 22 Feb 2005 04:35:57 -0000 1.176
--- src/backend/libpq/pqcomm.c 3 May 2005 01:44:03 -0000
***************
*** 87,93 ****
#include "libpq/libpq.h"
#include "miscadmin.h"
#include "storage/ipc.h"
!
/*
* Configuration options
--- 87,93 ----
#include "libpq/libpq.h"
#include "miscadmin.h"
#include "storage/ipc.h"
! #include "utils/guc.h"
/*
* Configuration options
***************
*** 577,582 ****
--- 577,583 ----
if (!IS_AF_UNIX(port->laddr.addr.ss_family))
{
int on;
+ socklen_t size;
#ifdef TCP_NODELAY
on = 1;
***************
*** 587,599 ****
return STATUS_ERROR;
}
#endif
! on = 1;
! if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
! (char *) &on, sizeof(on)) < 0)
{
! elog(LOG, "setsockopt(SO_KEEPALIVE) failed: %m");
return STATUS_ERROR;
}
}
return STATUS_OK;
--- 588,645 ----
return STATUS_ERROR;
}
#endif
!
! if (pq_setkeepalives(tcp_keepalives, port) != STATUS_OK)
! return STATUS_ERROR;
!
! /* Grab default keepalive values, then apply
! * our GUC settings.
! */
! #ifdef TCP_KEEPIDLE
! if (getsockopt(port->sock, SOL_TCP, TCP_KEEPIDLE,
! (char *)
&port->default_keepalives_idle, &size) < 0)
! {
! elog(LOG, "getsockopt(TCP_KEEPIDLE) failed: %m");
! return STATUS_ERROR;
! }
! #else
! port->default_keepalives_idle = 0;
! #endif
!
! #ifdef TCP_KEEPINTVL
! if (getsockopt(port->sock, SOL_TCP, TCP_KEEPINTVL,
! (char *)
&port->default_keepalives_interval, &size) < 0)
{
! elog(LOG, "getsockopt(TCP_KEEPINTVL) failed: %m");
return STATUS_ERROR;
}
+ #else
+ port->default_keepalives_idle = 0;
+ #endif
+
+ #ifdef TCP_KEEPCNT
+ if (getsockopt(port->sock, SOL_TCP, TCP_KEEPCNT,
+ (char *)
&port->default_keepalives_count, &size) < 0)
+ {
+ elog(LOG, "getsockopt(TCP_KEEPCNT) failed: %m");
+ return STATUS_ERROR;
+ }
+ #else
+ port->default_keepalives_idle = 0;
+ #endif
+
+ /* Set default keepalive parameters. This should also catch
+ * misconfigurations (non-zero values when socket options aren't
+ * supported)
+ */
+ if (pq_setkeepalivesidle(tcp_keepalives_idle, port) !=
STATUS_OK)
+ return STATUS_ERROR;
+
+ if (pq_setkeepalivesinterval(tcp_keepalives_interval, port) !=
STATUS_OK)
+ return STATUS_ERROR;
+
+ if (pq_setkeepalivescount(tcp_keepalives_count, port) !=
STATUS_OK)
+ return STATUS_ERROR;
}
return STATUS_OK;
***************
*** 1158,1160 ****
--- 1204,1305 ----
/* in non-error case, copy.c will have emitted the terminator line */
DoingCopyOut = false;
}
+
+ int
+ pq_setkeepalives(bool onoff, Port *port)
+ {
+ int on = (onoff ? 1 : 0);
+
+ if (IS_AF_UNIX(port->laddr.addr.ss_family))
+ return STATUS_OK;
+
+ if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
+ (char *) &on, sizeof(on)) < 0)
+ {
+ elog(LOG, "setsockopt(SO_KEEPALIVE) failed: %m");
+ return STATUS_ERROR;
+ }
+
+ return STATUS_OK;
+ }
+
+ int
+ pq_setkeepalivesidle(int idle, Port *port)
+ {
+ if (IS_AF_UNIX(port->laddr.addr.ss_family))
+ return STATUS_OK;
+
+ #ifdef TCP_KEEPIDLE
+ if (idle == 0)
+ idle = port->default_keepalives_idle;
+
+ if (setsockopt(port->sock, SOL_TCP, TCP_KEEPIDLE,
+ (char *) &idle, sizeof(idle)) < 0)
+ {
+ elog(LOG, "setsockopt(TCP_KEEPIDLE) failed: %m");
+ return STATUS_ERROR;
+ }
+ #else
+ if (idle != 0)
+ {
+ elog(LOG, "setsockopt(TCP_KEEPIDLE) not supported");
+ return STATUS_ERROR;
+ }
+ #endif
+
+ return STATUS_OK;
+ }
+
+ int
+ pq_setkeepalivesinterval(int interval, Port *port)
+ {
+ if (IS_AF_UNIX(port->laddr.addr.ss_family))
+ return STATUS_OK;
+
+ #ifdef TCP_KEEPINTVL
+ if (interval == 0)
+ interval = port->default_keepalives_interval;
+
+ if (setsockopt(port->sock, SOL_TCP, TCP_KEEPINTVL,
+ (char *) &interval, sizeof(interval)) < 0)
+ {
+ elog(LOG, "setsockopt(TCP_KEEPINTVL) failed: %m");
+ return STATUS_ERROR;
+ }
+ #else
+ if (interval != 0)
+ {
+ elog(LOG, "setsockopt(TCP_KEEPINTVL) not supported");
+ return STATUS_ERROR;
+ }
+ #endif
+
+ return STATUS_OK;
+ }
+
+ int
+ pq_setkeepalivescount(int count, Port *port)
+ {
+ if (IS_AF_UNIX(port->laddr.addr.ss_family))
+ return STATUS_OK;
+
+ #ifdef TCP_KEEPCNT
+ if (count == 0)
+ count = port->default_keepalives_count;
+
+ if (setsockopt(port->sock, SOL_TCP, TCP_KEEPCNT,
+ (char *) &count, sizeof(count)) < 0)
+ {
+ elog(LOG, "setsockopt(TCP_KEEPCNT) failed: %m");
+ return STATUS_ERROR;
+ }
+ #else
+ if (count != 0)
+ {
+ elog(LOG, "setsockopt(TCP_KEEPCNT) not supported");
+ return STATUS_ERROR;
+ }
+ #endif
+
+ return STATUS_OK;
+ }
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/misc/guc.c,v
retrieving revision 1.261
diff -c -r1.261 guc.c
*** src/backend/utils/misc/guc.c 1 May 2005 18:56:19 -0000 1.261
--- src/backend/utils/misc/guc.c 3 May 2005 01:44:08 -0000
***************
*** 113,118 ****
--- 113,125 ----
static bool assign_transaction_read_only(bool newval, bool doit, GucSource
source);
static const char *assign_canonical_path(const char *newval, bool doit,
GucSource source);
+ static bool assign_tcp_keepalives(bool newval, bool doit, GucSource source);
+ static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource
source);
+ static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource
source);
+ static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource
source);
+ static const char *show_tcp_keepalives_idle(void);
+ static const char *show_tcp_keepalives_interval(void);
+ static const char *show_tcp_keepalives_count(void);
/*
* GUC option variables that are exported from this module
***************
*** 154,159 ****
--- 161,170 ----
char *IdentFileName;
char *external_pid_file;
+ bool tcp_keepalives = true;
+ int tcp_keepalives_idle;
+ int tcp_keepalives_interval;
+ int tcp_keepalives_count;
/*
* These variables are all dummies that don't do anything, except in some
***************
*** 860,865 ****
--- 871,885 ----
#endif
},
+ {
+ {"tcp_keepalives", PGC_USERSET, CLIENT_CONN_OTHER,
+ gettext_noop("Use keepalives on client TCP connections."),
+ NULL,
+ },
+ &tcp_keepalives,
+ true, assign_tcp_keepalives, NULL
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
***************
*** 1333,1338 ****
--- 1353,1387 ----
BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
},
+ {
+ {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
+ gettext_noop("Seconds between issuing TCP keepalives."),
+ gettext_noop("A value of 0 uses the system default."),
+ },
+ &tcp_keepalives_idle,
+ 0, 0, INT_MAX, assign_tcp_keepalives_idle,
show_tcp_keepalives_idle
+ },
+
+ {
+ {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
+ gettext_noop("Seconds between TCP keepalive retransmits."),
+ gettext_noop("A value of 0 uses the system default."),
+ },
+ &tcp_keepalives_interval,
+ 0, 0, INT_MAX, assign_tcp_keepalives_interval,
show_tcp_keepalives_interval
+ },
+
+ {
+ {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
+ gettext_noop("Maximum number of TCP keepalive
retransmits."),
+ gettext_noop("This controls the number of consecutive
keepalive retransmits that can be "
+ "lost before a connection is
considered dead. A value of 0 uses the "
+ "system default."),
+ },
+ &tcp_keepalives_count,
+ 0, 0, INT_MAX, assign_tcp_keepalives_count,
show_tcp_keepalives_count
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
***************
*** 5677,5681 ****
--- 5726,5802 ----
return newval;
}
+ static bool
+ assign_tcp_keepalives(bool newval, bool doit, GucSource source)
+ {
+ if (doit && MyProcPort != NULL)
+ {
+ pq_setkeepalives(newval, MyProcPort);
+ }
+ return true;
+ }
+
+ static bool
+ assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
+ {
+ if (doit && MyProcPort != NULL)
+ {
+ return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
+ }
+
+ return true;
+ }
+
+ static const char *
+ show_tcp_keepalives_idle(void)
+ {
+ static char nbuf[32];
+ snprintf(nbuf, sizeof(nbuf), "%d",
+ (tcp_keepalives_idle != 0 || MyProcPort == NULL)
+ ? tcp_keepalives_idle :
MyProcPort->default_keepalives_idle);
+ return nbuf;
+ }
+
+ static bool
+ assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
+ {
+ if (doit && MyProcPort != NULL)
+ {
+ return (pq_setkeepalivesinterval(newval, MyProcPort) ==
STATUS_OK);
+ }
+
+ return true;
+ }
+
+ static const char *
+ show_tcp_keepalives_interval(void)
+ {
+ static char nbuf[32];
+ snprintf(nbuf, sizeof(nbuf), "%d",
+ (tcp_keepalives_interval != 0 || MyProcPort == NULL)
+ ? tcp_keepalives_interval :
MyProcPort->default_keepalives_interval);
+ return nbuf;
+ }
+
+ static bool
+ assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
+ {
+ if (doit && MyProcPort != NULL)
+ {
+ return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
+ }
+
+ return true;
+ }
+
+ static const char *
+ show_tcp_keepalives_count(void)
+ {
+ static char nbuf[32];
+ snprintf(nbuf, sizeof(nbuf), "%d",
+ (tcp_keepalives_count != 0 || MyProcPort == NULL)
+ ? tcp_keepalives_count :
MyProcPort->default_keepalives_count);
+ return nbuf;
+ }
#include "guc-file.c"
Index: src/backend/utils/misc/postgresql.conf.sample
===================================================================
RCS file:
/projects/cvsroot/pgsql/src/backend/utils/misc/postgresql.conf.sample,v
retrieving revision 1.140
diff -c -r1.140 postgresql.conf.sample
*** src/backend/utils/misc/postgresql.conf.sample 21 Apr 2005 19:18:13
-0000 1.140
--- src/backend/utils/misc/postgresql.conf.sample 3 May 2005 01:44:08
-0000
***************
*** 66,71 ****
--- 66,77 ----
#krb_server_keyfile = ''
#db_user_namespace = false
+ # - TCP Keepalives -
+ # see 'man 7 tcp' for details
+ #tcp_keepalives = on # enables use of TCP keepalives
+ #tcp_keepalives_idle = 0 # TCP_KEEPIDLE, in seconds; 0 uses the system
default.
+ #tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds; 0 uses the
system default.
+ #tcp_keepalives_count = 0 # TCP_KEEPCNT, in seconds; 0 uses the system
default.
#---------------------------------------------------------------------------
# RESOURCE USAGE (except WAL)
Index: src/bin/psql/tab-complete.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/bin/psql/tab-complete.c,v
retrieving revision 1.125
diff -c -r1.125 tab-complete.c
*** src/bin/psql/tab-complete.c 21 Apr 2005 19:18:13 -0000 1.125
--- src/bin/psql/tab-complete.c 3 May 2005 01:44:10 -0000
***************
*** 595,600 ****
--- 595,604 ----
"superuser_reserved_connections",
"syslog_facility",
"syslog_ident",
+ "tcp_keepalives",
+ "tcp_keepalives_idle",
+ "tcp_keepalives_interval",
+ "tcp_keepalives_count",
"temp_buffers",
"TimeZone",
"trace_notify",
Index: src/include/libpq/libpq-be.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/libpq/libpq-be.h,v
retrieving revision 1.49
diff -c -r1.49 libpq-be.h
*** src/include/libpq/libpq-be.h 31 Dec 2004 22:03:32 -0000 1.49
--- src/include/libpq/libpq-be.h 3 May 2005 01:44:10 -0000
***************
*** 92,100 ****
--- 92,113 ----
char peer_cn[SM_USER + 1];
unsigned long count;
#endif
+
+ /*
+ * Default TCP keepalive values found after accept(); 0 if unsupported
or AF_UNIX.
+ */
+ int default_keepalives_idle;
+ int default_keepalives_interval;
+ int default_keepalives_count;
} Port;
extern ProtocolVersion FrontendProtocol;
+ /* TCP keepalives configuration. These are no-ops on an AF_UNIX socket. */
+ extern int pq_setkeepalives(bool onoff, Port *port);
+ extern int pq_setkeepalivesidle(int idle, Port *port);
+ extern int pq_setkeepalivesinterval(int interval, Port *port);
+ extern int pq_setkeepalivescount(int count, Port *port);
+
#endif /* LIBPQ_BE_H */
Index: src/include/utils/guc.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/utils/guc.h,v
retrieving revision 1.60
diff -c -r1.60 guc.h
*** src/include/utils/guc.h 25 Mar 2005 16:17:28 -0000 1.60
--- src/include/utils/guc.h 3 May 2005 01:44:10 -0000
***************
*** 133,138 ****
--- 133,142 ----
extern char *IdentFileName;
extern char *external_pid_file;
+ extern bool tcp_keepalives;
+ extern int tcp_keepalives_idle;
+ extern int tcp_keepalives_interval;
+ extern int tcp_keepalives_count;
extern void SetConfigOption(const char *name, const char *value,
GucContext context, GucSource source);
---------------------------(end of broadcast)---------------------------
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