Re: Implement support for TCP_KEEPCNT, TCP_KEEPIDLE, TCP_KEEPINTVL - Mailing list pgsql-patches

Bruce Momjian wrote:
> Is this patch being worked on?

Here's an updated version. It compiles and appears to work as expected
under Linux (supports TCP_KEEPIDLE etc) and Solaris 9 (no support).

Main changes:

- removed the tcp_keepalives GUC, SO_KEEPALIVE is now always on (as in
current CVS)
- {get,set}sockopt calls are only done when absolutely necessary (no
extra syscalls during backend startup in a default configuration).

I still haven't had a chance to glue in support for the TCP_KEEPALIVE
(Solaris-style) option, but that should be fairly painless to add later.

-O
? postgresql-8.1devel.tar.gz
Index: doc/src/sgml/runtime.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/runtime.sgml,v
retrieving revision 1.335
diff -u -c -r1.335 runtime.sgml
*** doc/src/sgml/runtime.sgml    2 Jul 2005 19:16:36 -0000    1.335
--- doc/src/sgml/runtime.sgml    4 Jul 2005 10:41:33 -0000
***************
*** 894,899 ****
--- 894,946 ----
        </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.
+        </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.
+        </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.
+        </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 -u -c -r1.176 pqcomm.c
*** src/backend/libpq/pqcomm.c    22 Feb 2005 04:35:57 -0000    1.176
--- src/backend/libpq/pqcomm.c    4 Jul 2005 10:41:33 -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
***************
*** 594,599 ****
--- 594,612 ----
              elog(LOG, "setsockopt(SO_KEEPALIVE) failed: %m");
              return STATUS_ERROR;
          }
+
+         /* 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 ****
--- 1171,1369 ----
      /* in non-error case, copy.c will have emitted the terminator line */
      DoingCopyOut = false;
  }
+
+ int
+ pq_getkeepalivesidle(Port *port)
+ {
+ #ifdef TCP_KEEPIDLE
+     if (IS_AF_UNIX(port->laddr.addr.ss_family))
+         return 0;
+
+     if (port->keepalives_idle != 0)
+         return port->keepalives_idle;
+
+     if (port->default_keepalives_idle == 0)
+     {
+         socklen_t size = sizeof(port->default_keepalives_idle);
+         if (getsockopt(port->sock, SOL_TCP, TCP_KEEPIDLE,
+                        (char *) &port->default_keepalives_idle,
+                        &size) < 0)
+         {
+             elog(LOG, "getsockopt(TCP_KEEPIDLE) failed: %m");
+             return -1;
+         }
+     }
+
+     return port->default_keepalives_idle;
+ #else
+     return 0;
+ #endif
+ }
+
+ int
+ pq_setkeepalivesidle(int idle, Port *port)
+ {
+     if (IS_AF_UNIX(port->laddr.addr.ss_family))
+         return STATUS_OK;
+
+ #ifdef TCP_KEEPIDLE
+     if (idle == port->keepalives_idle)
+         return STATUS_OK;
+
+     if (port->default_keepalives_idle == 0)
+     {
+         if (pq_getkeepalivesidle(port) < 0)
+             return STATUS_ERROR;
+     }
+
+     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;
+     }
+
+     port->keepalives_idle = idle;
+ #else
+     if (idle != 0)
+     {
+         elog(LOG, "setsockopt(TCP_KEEPIDLE) not supported");
+         return STATUS_ERROR;
+     }
+ #endif
+
+     return STATUS_OK;
+ }
+
+ int
+ pq_getkeepalivesinterval(Port *port)
+ {
+ #ifdef TCP_KEEPINTVL
+     if (IS_AF_UNIX(port->laddr.addr.ss_family))
+         return 0;
+
+     if (port->keepalives_interval != 0)
+         return port->keepalives_interval;
+
+     if (port->default_keepalives_interval == 0)
+     {
+         socklen_t size = sizeof(port->default_keepalives_interval);
+         if (getsockopt(port->sock, SOL_TCP, TCP_KEEPINTVL,
+                        (char *) &port->default_keepalives_interval,
+                        &size) < 0)
+         {
+             elog(LOG, "getsockopt(TCP_KEEPINTVL) failed: %m");
+             return -1;
+         }
+     }
+
+     return port->default_keepalives_interval;
+ #else
+     return 0;
+ #endif
+ }
+
+ int
+ pq_setkeepalivesinterval(int interval, Port *port)
+ {
+     if (IS_AF_UNIX(port->laddr.addr.ss_family))
+         return STATUS_OK;
+
+ #ifdef TCP_KEEPINTVL
+     if (interval == port->keepalives_interval)
+         return STATUS_OK;
+
+     if (port->default_keepalives_interval == 0) {
+         if (pq_getkeepalivesinterval(port) < 0)
+             return STATUS_ERROR;
+     }
+
+     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;
+     }
+
+     port->keepalives_interval = interval;
+ #else
+     if (interval != 0)
+     {
+         elog(LOG, "setsockopt(TCP_KEEPINTVL) not supported");
+         return STATUS_ERROR;
+     }
+ #endif
+
+     return STATUS_OK;
+ }
+
+ int
+ pq_getkeepalivescount(Port *port)
+ {
+ #ifdef TCP_KEEPCNT
+     if (IS_AF_UNIX(port->laddr.addr.ss_family))
+         return 0;
+
+     if (port->keepalives_count != 0)
+         return port->keepalives_count;
+
+     if (port->default_keepalives_count == 0)
+     {
+         socklen_t size = sizeof(port->default_keepalives_count);
+         if (getsockopt(port->sock, SOL_TCP, TCP_KEEPCNT,
+                        (char *) &port->default_keepalives_count,
+                        &size) < 0)
+         {
+             elog(LOG, "getsockopt(TCP_KEEPCNT) failed: %m");
+             return -1;
+         }
+     }
+
+     return port->default_keepalives_count;
+ #else
+     return 0;
+ #endif
+ }
+
+ int
+ pq_setkeepalivescount(int count, Port *port)
+ {
+     if (IS_AF_UNIX(port->laddr.addr.ss_family))
+         return STATUS_OK;
+
+ #ifdef TCP_KEEPCNT
+     if (count == port->keepalives_count)
+         return STATUS_OK;
+
+     if (port->default_keepalives_count == 0) {
+         if (pq_getkeepalivescount(port) < 0)
+             return STATUS_ERROR;
+     }
+
+     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;
+     }
+
+     port->keepalives_count = count;
+ #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 1.271
diff -u -c -r1.271 guc.c
*** src/backend/utils/misc/guc.c    28 Jun 2005 05:09:02 -0000    1.271
--- src/backend/utils/misc/guc.c    4 Jul 2005 10:41:33 -0000
***************
*** 117,122 ****
--- 117,128 ----
  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_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
***************
*** 158,163 ****
--- 164,172 ----
  char       *IdentFileName;
  char       *external_pid_file;

+ 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
***************
*** 1375,1380 ****
--- 1384,1418 ----
          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
***************
*** 5744,5748 ****
--- 5782,5842 ----
          return newval;
  }

+ 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", MyProcPort == NULL ? 0 : pq_getkeepalivesidle(MyProcPort));
+     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", MyProcPort == NULL ? 0 : pq_getkeepalivesinterval(MyProcPort));
+     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", MyProcPort == NULL ? 0 : pq_getkeepalivescount(MyProcPort));
+     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 1.151
diff -u -c -r1.151 postgresql.conf.sample
*** src/backend/utils/misc/postgresql.conf.sample    2 Jul 2005 18:46:45 -0000    1.151
--- src/backend/utils/misc/postgresql.conf.sample    4 Jul 2005 10:41:33 -0000
***************
*** 70,75 ****
--- 70,80 ----
  #krb_caseins_users = off
  #krb_srvname = 'postgres'

+ # - TCP Keepalives -
+ # see 'man 7 tcp' for details
+ #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 1.133
diff -u -c -r1.133 tab-complete.c
*** src/bin/psql/tab-complete.c    22 Jun 2005 21:14:30 -0000    1.133
--- src/bin/psql/tab-complete.c    4 Jul 2005 10:41:33 -0000
***************
*** 600,605 ****
--- 600,608 ----
          "superuser_reserved_connections",
          "syslog_facility",
          "syslog_ident",
+         "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 -u -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    4 Jul 2005 10:41:33 -0000
***************
*** 25,30 ****
--- 25,33 ----
  #include <openssl/ssl.h>
  #include <openssl/err.h>
  #endif
+ #ifdef HAVE_NETINET_TCP_H
+ #include <netinet/tcp.h>
+ #endif

  #include "libpq/hba.h"
  #include "libpq/pqcomm.h"
***************
*** 92,100 ****
--- 95,131 ----
      char        peer_cn[SM_USER + 1];
      unsigned long count;
  #endif
+
+     /*
+      * TCP keepalive settings;
+      *  default values are 0 if AF_UNIX or not yet known;
+      *  current values are 0 if AF_UNIX or using the default.
+      */
+ #ifdef TCP_KEEPIDLE
+     int         default_keepalives_idle;
+     int         keepalives_idle;
+ #endif
+ #ifdef TCP_KEEPINTVL
+     int         default_keepalives_interval;
+     int         keepalives_interval;
+ #endif
+ #ifdef TCP_KEEPCNT
+     int         default_keepalives_count;
+     int         keepalives_count;
+ #endif
  } Port;


  extern ProtocolVersion FrontendProtocol;

+ /* TCP keepalives configuration. These are no-ops on an AF_UNIX socket. */
+
+ extern int pq_getkeepalivesidle(Port *port);
+ extern int pq_getkeepalivesinterval(Port *port);
+ extern int pq_getkeepalivescount(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 1.61
diff -u -c -r1.61 guc.h
*** src/include/utils/guc.h    26 Jun 2005 03:04:12 -0000    1.61
--- src/include/utils/guc.h    4 Jul 2005 10:41:33 -0000
***************
*** 134,139 ****
--- 134,142 ----
  extern char *IdentFileName;
  extern char *external_pid_file;

+ 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);