From: Robert Haas Date: Wed, 23 Jun 2010 21:54:13 +0000 (+0000) Subject: Add TCP keepalive support to libpq. X-Git-Tag: REL9_0_BETA3~77 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d8cd283a08fe87579e3603eaa8fba4d1eca6a8ca;p=postgresql Add TCP keepalive support to libpq. This adds four additional connection parameters to libpq: keepalives, keepalives_idle, keepalives_count, and keepalives_interval. keepalives default to on, per discussion, but can be turned off by specifying keepalives=0. The remaining parameters, where supported, can be used to adjust how often keepalives are sent and how many can be lost before the connection is broken. The immediate motivation for this patch is to make sure that walreceiver will eventually notice if the master reboots without closing the connection cleanly, but it should be helpful in other cases as well. Tollef Fog Heen, Fujii Masao, and me. --- diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index d3a2218182..11161d993f 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -1,4 +1,4 @@ - + <application>libpq</application> - C Library @@ -280,6 +280,57 @@ + + keepalives + + + Controls whether TCP keepalives are used. The default value is 1, + meaning on, but you can change this to 0, meaning off, if keepalives + are not wanted. This parameter is ignored for connections made via + a Unix-domain socket. + + + + + + keepalives_idle + + + 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 zero uses the system + default. This parameter is ignored for connections made via a + Unix-domain socket, or if keepalives are disabled. + + + + + + keepalives_interval + + + 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 zero uses the system + default. This parameter is ignored for connections made via a + Unix-domain socket, or if keepalives are disabled. + + + + + + keepalives_count + + + On systems that support the TCP_KEEPCNT socket + option, specifies how many keepalives can be lost before the + connection is considered dead. A value of zero uses the system + default. This parameter is ignored for connections made via a + Unix-domain socket, or if keepalives are disabled. + + + + tty diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c index 3a1465457e..795b64e55b 100644 --- a/src/interfaces/libpq/fe-connect.c +++ b/src/interfaces/libpq/fe-connect.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.393 2010/05/26 21:39:27 tgl Exp $ + * $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.394 2010/06/23 21:54:13 rhaas Exp $ * *------------------------------------------------------------------------- */ @@ -183,6 +183,18 @@ static const PQconninfoOption PQconninfoOptions[] = { {"fallback_application_name", NULL, NULL, NULL, "Fallback-Application-Name", "", 64}, + {"keepalives", NULL, NULL, NULL, + "TCP-Keepalives", "", 1}, /* should be just '0' or '1' */ + + {"keepalives_idle", NULL, NULL, NULL, + "TCP-Keepalives-Idle", "", 10}, /* strlen(INT32_MAX) == 10 */ + + {"keepalives_interval", NULL, NULL, NULL, + "TCP-Keepalives-Interval", "", 10}, /* strlen(INT32_MAX) == 10 */ + + {"keepalives_count", NULL, NULL, NULL, + "TCP-Keepalives-Count", "", 10}, /* strlen(INT32_MAX) == 10 */ + #ifdef USE_SSL /* @@ -552,6 +564,14 @@ fillPGconn(PGconn *conn, PQconninfoOption *connOptions) conn->pgpass = tmp ? strdup(tmp) : NULL; tmp = conninfo_getval(connOptions, "connect_timeout"); conn->connect_timeout = tmp ? strdup(tmp) : NULL; + tmp = conninfo_getval(connOptions, "keepalives"); + conn->keepalives = tmp ? strdup(tmp) : NULL; + tmp = conninfo_getval(connOptions, "keepalives_idle"); + conn->keepalives_idle = tmp ? strdup(tmp) : NULL; + tmp = conninfo_getval(connOptions, "keepalives_interval"); + conn->keepalives_interval = tmp ? strdup(tmp) : NULL; + tmp = conninfo_getval(connOptions, "keepalives_count"); + conn->keepalives_count = tmp ? strdup(tmp) : NULL; tmp = conninfo_getval(connOptions, "sslmode"); conn->sslmode = tmp ? strdup(tmp) : NULL; tmp = conninfo_getval(connOptions, "sslkey"); @@ -943,6 +963,119 @@ connectFailureMessage(PGconn *conn, int errorno) } } +/* + * Should we use keepalives? Returns 1 if yes, 0 if no, and -1 if + * conn->keepalives is set to a value which is not parseable as an + * integer. + */ +static int +useKeepalives(PGconn *conn) +{ + char *ep; + int val; + + if (conn->keepalives == NULL) + return 1; + val = strtol(conn->keepalives, &ep, 10); + if (*ep) + return -1; + return val != 0 ? 1 : 0; +} + +/* + * Set the keepalive idle timer. + */ +static int +setKeepalivesIdle(PGconn *conn) +{ + int idle; + + if (conn->keepalives_idle == NULL) + return 1; + + idle = atoi(conn->keepalives_idle); + if (idle < 0) + idle = 0; + +#ifdef TCP_KEEPIDLE + if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPIDLE, + (char *) &idle, sizeof(idle)) < 0) + { + char sebuf[256]; + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("setsockopt(TCP_KEEPIDLE) failed: %s\n"), + SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); + return 0; + } +#endif + + return 1; +} + +/* + * Set the keepalive interval. + */ +static int +setKeepalivesInterval(PGconn *conn) +{ + int interval; + + if (conn->keepalives_interval == NULL) + return 1; + + interval = atoi(conn->keepalives_interval); + if (interval < 0) + interval = 0; + +#ifdef TCP_KEEPINTVL + if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPINTVL, + (char *) &interval, sizeof(interval)) < 0) + { + char sebuf[256]; + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("setsockopt(TCP_KEEPINTVL) failed: %s\n"), + SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); + return 0; + } +#endif + + return 1; +} + +/* + * Set the count of lost keepalive packets that will trigger a connection + * break. + */ +static int +setKeepalivesCount(PGconn *conn) +{ + int count; + + if (conn->keepalives_count == NULL) + return 1; + + count = atoi(conn->keepalives_count); + if (count < 0) + count = 0; + +#ifdef TCP_KEEPCNT + if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPCNT, + (char *) &count, sizeof(count)) < 0) + { + char sebuf[256]; + + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("setsockopt(TCP_KEEPCNT) failed: %s\n"), + SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); + return 0; + } +#endif + + return 1; +} + /* ---------- * connectDBStart - @@ -1329,6 +1462,45 @@ keep_going: /* We will come back to here until there is } #endif /* F_SETFD */ + if (!IS_AF_UNIX(addr_cur->ai_family)) + { + int on = 1; + int usekeepalives = useKeepalives(conn); + int err = 0; + + if (usekeepalives < 0) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("keepalives parameter must be an integer\n")); + err = 1; + } + else if (usekeepalives == 0) + { + /* Do nothing */ + } + else if (setsockopt(conn->sock, + SOL_SOCKET, SO_KEEPALIVE, + (char *) &on, sizeof(on)) < 0) + { + appendPQExpBuffer(&conn->errorMessage, + libpq_gettext("setsockopt(SO_KEEPALIVE) failed: %s\n"), + SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); + err = 1; + } + else if (!setKeepalivesIdle(conn) + || !setKeepalivesInterval(conn) + || !setKeepalivesCount(conn)) + err = 1; + + if (err) + { + closesocket(conn->sock); + conn->sock = -1; + conn->addr_cur = addr_cur->ai_next; + continue; + } + } + /*---------- * We have three methods of blocking SIGPIPE during * send() calls to this socket: @@ -2290,6 +2462,14 @@ freePGconn(PGconn *conn) free(conn->pguser); if (conn->pgpass) free(conn->pgpass); + if (conn->keepalives) + free(conn->keepalives); + if (conn->keepalives_idle) + free(conn->keepalives_idle); + if (conn->keepalives_interval) + free(conn->keepalives_interval); + if (conn->keepalives_count) + free(conn->keepalives_count); if (conn->sslmode) free(conn->sslmode); if (conn->sslcert) diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h index 6fe96ab168..23b914abbc 100644 --- a/src/interfaces/libpq/libpq-int.h +++ b/src/interfaces/libpq/libpq-int.h @@ -12,7 +12,7 @@ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.150 2010/03/13 14:55:57 momjian Exp $ + * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.151 2010/06/23 21:54:13 rhaas Exp $ * *------------------------------------------------------------------------- */ @@ -300,6 +300,10 @@ struct pg_conn char *replication; /* connect as the replication standby? */ char *pguser; /* Postgres username and password, if any */ char *pgpass; + char *keepalives; /* use TCP keepalives? */ + char *keepalives_idle; /* time between TCP keepalives */ + char *keepalives_interval; /* time between TCP keepalive retransmits */ + char *keepalives_count; /* maximum number of TCP keepalive retransmits */ char *sslmode; /* SSL mode (require,prefer,allow,disable) */ char *sslkey; /* client key filename */ char *sslcert; /* client certificate filename */