On Mon, 07 Dec 2015 15:26:33 -0500
Korry Douglas <[email protected]> wrote:
> The problem seems to be in PQconnectPoll() in the case for
> CONNECTION_AUTH_OK, specifically this code:
>
> /* We can release the address list now. */
> pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
> conn->addrlist = NULL;
> conn->addr_cur = NULL;
> That frees up the list of alternative host addresses. The state
> machine then progresses to CONNECTION_CHECK_RO (which invokes
> pg_is_in_recovery()), then CONNECTION_CHECK_RW (waiting for the
Thank you for pointing to this problem. I've overlooked it. Probably
I should improve my testing scenario.
I', attaching new version of the patch, which, hopefully, handles
address list freeing correctly.
--
Victor Wagner <[email protected]>
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 9c0e4c8..162bd4f 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -792,7 +792,7 @@ host=localhost port=5432 dbname=mydb connect_timeout=10
<para>
The general form for a connection <acronym>URI</acronym> is:
<synopsis>
-postgresql://[user[:password]@][netloc][:port][/dbname][?param1=value1&...]
+postgresql://[user[:password]@][netloc][:port][,netloc[:port]...][/dbname][?param1=value1&...]
</synopsis>
</para>
@@ -809,6 +809,7 @@ postgresql://localhost/mydb
postgresql://user@localhost
postgresql://user:secret@localhost
postgresql://other@localhost/otherdb?connect_timeout=10&application_name=myapp
+postgresql://node1,node2:5433,node3:4432,node4/mydb?hostorder=random&readonly=1
</programlisting>
Components of the hierarchical part of the <acronym>URI</acronym> can also
be given as parameters. For example:
@@ -831,7 +832,9 @@ postgresql:///mydb?host=localhost&port=5433
<para>
For improved compatibility with JDBC connection <acronym>URI</acronym>s,
instances of parameter <literal>ssl=true</literal> are translated into
- <literal>sslmode=require</literal>.
+ <literal>sslmode=require</literal> and
+ <literal>loadBalanceHosts=true</literal> into
+ <literal>hostorder=random</literal>.
</para>
<para>
@@ -841,6 +844,10 @@ postgresql:///mydb?host=localhost&port=5433
postgresql://[2001:db8::1234]/database
</synopsis>
</para>
+ <para>
+ There can be serveral host specifications, optionally accompanied
+ with port, separated by comma.
+ </para>
<para>
The host component is interpreted as described for the parameter <xref
@@ -881,6 +888,20 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
when <productname>PostgreSQL</> was built). On machines without
Unix-domain sockets, the default is to connect to <literal>localhost</>.
</para>
+ <para>
+ There can be more than one <literal>host</literal> parameter in
+ the connect string. In this case these hosts would be considered
+ alternate entries into same database and if connect to first one
+ fails, library would try to connect second etc. This can be used
+ for high availability cluster or for load balancing. See
+ <xref linkend="libpq-connect-hostorder"> parameter.
+ </para>
+ <para>
+ Network host name can be accompanied with port number, separated by
+ colon. If so, this port number is used only when connected to
+ this host. If there is no port number, port specified in the
+ <xref linkend="libpq-connect-port"> parameter would be used.
+ </para>
</listitem>
</varlistentry>
@@ -942,8 +963,44 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
</para>
</listitem>
</varlistentry>
-
+
+ <varlistentry id="libpq-connect-hostorder" xreflabel="hostorder">
+ <term><literal>hostorder</literal></term>
+ <listitem>
+ <para>
+ Specifies how to choose host from list of alternate hosts,
+ specified in the <xref linkend="libpq-connect-host"> parameter.
+ </para>
+ <para>
+ If value of this argument is <literal>sequential</literal> (the
+ default) library connects to the hosts in order they specified,
+ and tries to connect second one only if connection to the first
+ fails.
+ </para>
+ <para>
+ If value is <literal>random</literal> host to connect is randomly
+ picked from the list. It allows to balance load between several
+ cluster nodes. However, currently PostgreSQL doesn't support
+ multimaster clusters. So, without use of third-party products,
+ only read-only connections can take advantage from the
+ load-balancing. See <xref linkend="libpq-connect-readonly">
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry id="libpq-connect-readonly" xreflabel="readonly">
+ <term><literal>readonly</literal></term>
+ <listitem>
+ <para>
+ If this parameter is 0 (the default), upon successful connection
+ library checks if host is in recovery state, and if it is so,
+ tries next host in the connect string. If this parameter is
+ non-zero, connection to warm standby nodes are considered
+ successful.
+ </para>
+ </listitem>
+ </varlistentry>
<varlistentry id="libpq-connect-port" xreflabel="port">
+
<term><literal>port</literal></term>
<listitem>
<para>
@@ -985,7 +1042,6 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
</para>
</listitem>
</varlistentry>
-
<varlistentry id="libpq-connect-connect-timeout" xreflabel="connect_timeout">
<term><literal>connect_timeout</literal></term>
<listitem>
@@ -996,7 +1052,27 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
</para>
</listitem>
</varlistentry>
-
+ <varlistentry id="libpq-connect-falover-timeout" xreflabel="failover_timeout">
+ <term><literal>falover_timeout</literal></term>
+ <listitem>
+ <para>
+ Maximum time to cycilically retry all the hosts in commect string.
+ (as decimal integer number of seconds). If not specified, then
+ hosts are tried just once.
+ </para>
+ <para>
+ If we have replicating cluster, and master node fails, it might
+ take some time to promote one of standby nodes to the new master.
+ So clients which notice that connect to the master fails, can
+ already give up attempt to reestablish a connection when new master
+ became available.
+ </para>
+ <para>
+ Setting this parameter to reasonable time makes library try to
+ reconnect all the host in cyclically until new master appears.
+ </para>
+ </listitem>
+ </varlistentry>
<varlistentry id="libpq-connect-client-encoding" xreflabel="client_encoding">
<term><literal>client_encoding</literal></term>
<listitem>
@@ -7165,6 +7241,18 @@ user=admin
An example file is provided at
<filename>share/pg_service.conf.sample</filename>.
</para>
+ <para>
+ If more than one <literal>host</literal> option present in the section of service file, it
+ is interpeted as alternate servers for failover or load-balancing. See
+ <xref linkend="libpq-connect-host"> option in the connect string.
+ </para>
+ <para>
+ For all other options first value takes precedence over later ones.
+ </para>
+ <para>
+ Options, specified in the connect string along with service option
+ have precedence over values from the service file.
+ </para>
</sect1>
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 4a1a0272..ffc5daf 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -299,7 +299,16 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
{"replication", NULL, NULL, NULL,
"Replication", "D", 5,
offsetof(struct pg_conn, replication)},
-
+ /* Parameters added by failover patch */
+ {"hostorder", NULL, "sequential", NULL,
+ "Host order", "", 10,
+ offsetof(struct pg_conn, hostorder)},
+ {"readonly", NULL, "0", NULL,
+ "Read only", "", 1,
+ offsetof(struct pg_conn, read_only)},
+ {"failover_timeout", NULL, NULL, NULL,
+ "Failover Timoeut", "", 10,
+ offsetof(struct pg_conn, failover_timeout)},
/* Terminating entry --- MUST BE LAST */
{NULL, NULL, NULL, NULL,
NULL, NULL, 0}
@@ -336,6 +345,7 @@ static PGconn *makeEmptyPGconn(void);
static bool fillPGconn(PGconn *conn, PQconninfoOption *connOptions);
static void freePGconn(PGconn *conn);
static void closePGconn(PGconn *conn);
+static void pqTerminateConn(PGconn *conn);
static PQconninfoOption *conninfo_init(PQExpBuffer errorMessage);
static PQconninfoOption *parse_connection_string(const char *conninfo,
PQExpBuffer errorMessage, bool use_defaults);
@@ -380,6 +390,7 @@ static bool getPgPassFilename(char *pgpassfile);
static void dot_pg_pass_warning(PGconn *conn);
static void default_threadlock(int acquire);
+static int try_next_address(PGconn *conn);
/* global variable because fe-auth.c needs to access it */
pgthreadlock_t pg_g_threadlock = default_threadlock;
@@ -1390,11 +1401,17 @@ setKeepalivesWin32(PGconn *conn)
static int
connectDBStart(PGconn *conn)
{
+ struct nodeinfo
+ {
+ char *host;
+ char *port;
+ };
int portnum;
char portstr[MAXPGPATH];
struct addrinfo *addrs = NULL;
struct addrinfo hint;
- const char *node;
+ struct nodeinfo *nodes,
+ *node;
int ret;
if (!conn)
@@ -1436,21 +1453,78 @@ connectDBStart(PGconn *conn)
if (conn->pghostaddr != NULL && conn->pghostaddr[0] != '\0')
{
/* Using pghostaddr avoids a hostname lookup */
- node = conn->pghostaddr;
+
+ nodes = calloc(sizeof(struct nodeinfo), 2);
+ nodes->host = strdup(conn->pghostaddr);
hint.ai_family = AF_UNSPEC;
hint.ai_flags = AI_NUMERICHOST;
}
else if (conn->pghost != NULL && conn->pghost[0] != '\0')
{
/* Using pghost, so we have to look-up the hostname */
- node = conn->pghost;
+ char *p = conn->pghost,
+ *q,
+ *r;
+ int nodecount = 0,
+ nodesallocated = 4;
+ /* Parse comma-separated list of host-port pairs into
+ function-local array of records */
+ nodes = malloc(sizeof(struct nodeinfo) * 4);
+ while (*p)
+ {
+ q = p;
+ r = NULL;
+ /* Scan for the comma or end of string */
+ while (*q != ',' && *q != 0)
+ {
+ if (*q == ':')
+ r = q;
+ if (*q == ']')
+ r = NULL; /* if there is IPv6, colons before close
+ * bracket are part of address */
+ q++;
+ }
+ if (r)
+ {
+ /* Host has explicitely specified port */
+ nodes[nodecount].port = malloc(q - r );
+ strncpy(nodes[nodecount].port, r + 1 , q - r);
+ /* FIXME need to check that port is numeric */
+ nodes[nodecount].port[q - r - 1] = 0;
+ }
+ else
+ {
+ r = q;
+ nodes[nodecount].port = NULL;
+ }
+ if ((*p) == '[' && *(r - 1) == ']')
+ {
+ /* IPv6 address found. Strip brackets */
+ p++;
+ r--;
+ }
+ /* Fill node record */
+ nodes[nodecount].host = malloc(r - p + 1);
+ strncpy(nodes[nodecount].host, p, r - p);
+ nodes[nodecount].host[r - p] = 0;
+ /* skip a comma */
+ if (*q)
+ q++;
+ nodecount++;
+ if (nodecount == nodesallocated)
+ nodes = realloc(nodes, sizeof(struct nodeinfo) * (nodesallocated += 4));
+ p = q;
+ }
+ /* Fill end-of-host list marker */
+ nodes[nodecount].host = NULL;
+ nodes[nodecount].port = NULL;
hint.ai_family = AF_UNSPEC;
}
else
{
#ifdef HAVE_UNIX_SOCKETS
/* pghostaddr and pghost are NULL, so use Unix domain socket */
- node = NULL;
+ nodes = calloc(sizeof(struct nodeinfo), 2);
hint.ai_family = AF_UNIX;
UNIXSOCK_PATH(portstr, portnum, conn->pgunixsocket);
if (strlen(portstr) >= UNIXSOCK_PATH_BUFLEN)
@@ -1460,33 +1534,73 @@ connectDBStart(PGconn *conn)
portstr,
(int) (UNIXSOCK_PATH_BUFLEN - 1));
conn->options_valid = false;
+ free(nodes->port);
+ free(nodes);
goto connect_errReturn;
}
+ nodes->port = strdup(portstr);
#else
/* Without Unix sockets, default to localhost instead */
- node = DefaultHost;
+ nodes = calloc(sizeof(struct nodeinfo), 2);
+ nodes->host = strdup(DefaultHost);
hint.ai_family = AF_UNSPEC;
#endif /* HAVE_UNIX_SOCKETS */
}
/* Use pg_getaddrinfo_all() to resolve the address */
- ret = pg_getaddrinfo_all(node, portstr, &hint, &addrs);
- if (ret || !addrs)
- {
- if (node)
- appendPQExpBuffer(&conn->errorMessage,
- libpq_gettext("could not translate host name \"%s\" to address: %s\n"),
- node, gai_strerror(ret));
+ /* loop over all the host specs in the node variable */
+ for (node = nodes; node->host != NULL || node->port != NULL; node++)
+ {
+ struct addrinfo *this_node_addrs;
+ /* Resolve each hostname into list of addrinfo structures */
+ ret = pg_getaddrinfo_all(node->host, (node->port ? node->port : portstr),
+ &hint, &this_node_addrs);
+ if (ret || !this_node_addrs)
+ {
+ if (node->host)
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("could not translate host name \"%s\" to address: %s\n"),
+ node->host, gai_strerror(ret));
+ else
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("could not translate Unix-domain socket path \"%s\" to address: %s\n"),
+ node->port, gai_strerror(ret));
+ if (this_node_addrs)
+ pg_freeaddrinfo_all(hint.ai_family, this_node_addrs);
+
+ /*
+ * We shouldn't fail here unless there is no valid addrinfos left
+ */
+ continue;
+ }
+ /* add this host addrs to addrs field of PGconn structure */
+ if (!addrs)
+ {
+ addrs = this_node_addrs;
+ }
else
- appendPQExpBuffer(&conn->errorMessage,
- libpq_gettext("could not translate Unix-domain socket path \"%s\" to address: %s\n"),
- portstr, gai_strerror(ret));
- if (addrs)
- pg_freeaddrinfo_all(hint.ai_family, addrs);
+ {
+ struct addrinfo *p;
+
+ for (p = addrs; p->ai_next != NULL; p = p->ai_next);
+ p->ai_next = this_node_addrs;
+ }
+ }
+ /* Free nodes array */
+ for (node = nodes; node->host != NULL || node->port != NULL; node++)
+ {
+ if (node->host)
+ free(node->host);
+ if (node->port)
+ free(node->port);
+ }
+ free(nodes);
+ /* Check if we've found at least one usable address */
+ if (!addrs)
+ {
conn->options_valid = false;
goto connect_errReturn;
}
-
#ifdef USE_SSL
/* setup values based on SSL mode */
if (conn->sslmode[0] == 'd') /* "disable" */
@@ -1499,12 +1613,23 @@ connectDBStart(PGconn *conn)
* Set up to try to connect, with protocol 3.0 as the first attempt.
*/
conn->addrlist = addrs;
- conn->addr_cur = addrs;
+
+ /*
+ * We cannot just assign first addrs record to addr_cur, because host
+ * order may be random. So, use try_next_address
+ */
+ conn->addr_cur = NULL;
+ try_next_address(conn);
conn->addrlist_family = hint.ai_family;
conn->pversion = PG_PROTOCOL(3, 0);
conn->send_appname = true;
conn->status = CONNECTION_NEEDED;
-
+ if (conn->failover_timeout) {
+ conn->failover_finish_time = time(NULL) +
+ atoi(conn->failover_timeout);
+ } else {
+ conn->failover_finish_time = (time_t)0; /* it is in past, so its ok */
+ }
/*
* The code for processing CONNECTION_NEEDED state is in PQconnectPoll(),
* so that it can easily be re-executed if needed again during the
@@ -1603,6 +1728,76 @@ connectDBComplete(PGconn *conn)
}
}
+/* -------------
+ * try_next_address
+ * Attempts to set next address from the list of known ones.
+ * Returns 1 if address is choosen and 0 if there are no more addresses
+ * to try
+ * Takes into account hostorder parameter
+ * ------------
+ */
+
+static int
+try_next_address(PGconn *conn)
+{
+ if (strcmp(conn->hostorder, "sequential") == 0)
+ {
+ if (conn->addr_cur == NULL)
+ {
+ conn->addr_cur = conn->addrlist;
+ return 1;
+ }
+ else
+ {
+ conn->addr_cur = conn->addr_cur->ai_next;
+ if (conn->addr_cur == NULL && time(NULL) < conn->failover_finish_time) {
+ /* If failover timeout is set, retry list of hosts from
+ * the beginning */
+ conn->addr_cur = conn->addrlist;
+ }
+ return (conn->addr_cur != NULL);
+ }
+ }
+ else if (strcmp(conn->hostorder, "random") == 0)
+ {
+ struct addrinfo *choice = NULL,
+ *current = conn->addrlist;
+ int count = 0;
+ /* Initialize random number generator in case if nobody have
+ * done it before. Use value from rand along with time in case
+ * random number have been initialized by application.
+ * Use address of conn structure to load-balance different
+ * connections in the same app
+ */
+ srand((unsigned int)((long int)conn ^ (long int) time(NULL) ^
+ (long int)rand()));
+ while (current != NULL)
+ {
+ if (current == conn->addr_cur)
+ {
+ current = current->ai_next;
+ }
+ count++;
+ if ((rand()&0xffff) < 0x10000 / count)
+ {
+ choice = current;
+ }
+ current = current->ai_next;
+ }
+ if (choice == NULL)
+ return 0;
+ conn->addr_cur = choice;
+ return 1;
+ }
+ else if (strcmp(conn->hostorder, "parallel") == 0)
+ {
+ /* Not implemented yet */
+ return 0;
+ }
+ return 0;
+
+}
+
/* ----------------
* PQconnectPoll
*
@@ -1680,7 +1875,8 @@ PQconnectPoll(PGconn *conn)
case CONNECTION_SSL_STARTUP:
case CONNECTION_NEEDED:
break;
-
+ case CONNECTION_CHECK_RW:
+ break;
default:
appendPQExpBufferStr(&conn->errorMessage,
libpq_gettext(
@@ -1718,9 +1914,8 @@ keep_going: /* We will come back to here until there is
* ignore socket() failure if we have more addresses
* to try
*/
- if (addr_cur->ai_next != NULL)
+ if (try_next_address(conn))
{
- conn->addr_cur = addr_cur->ai_next;
continue;
}
appendPQExpBuffer(&conn->errorMessage,
@@ -1739,7 +1934,7 @@ keep_going: /* We will come back to here until there is
if (!connectNoDelay(conn))
{
pqDropConnection(conn, true);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
}
@@ -1749,7 +1944,7 @@ keep_going: /* We will come back to here until there is
libpq_gettext("could not set socket to nonblocking mode: %s\n"),
SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
pqDropConnection(conn, true);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
@@ -1760,7 +1955,7 @@ keep_going: /* We will come back to here until there is
libpq_gettext("could not set socket to close-on-exec mode: %s\n"),
SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
pqDropConnection(conn, true);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
#endif /* F_SETFD */
@@ -1807,7 +2002,7 @@ keep_going: /* We will come back to here until there is
if (err)
{
pqDropConnection(conn, true);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
}
@@ -1898,7 +2093,7 @@ keep_going: /* We will come back to here until there is
/*
* Try the next address, if any.
*/
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
} /* loop over addresses */
/*
@@ -1944,9 +2139,8 @@ keep_going: /* We will come back to here until there is
* If more addresses remain, keep trying, just as in the
* case where connect() returned failure immediately.
*/
- if (conn->addr_cur->ai_next != NULL)
+ if (try_next_address(conn))
{
- conn->addr_cur = conn->addr_cur->ai_next;
conn->status = CONNECTION_NEEDED;
goto keep_going;
}
@@ -2599,10 +2793,6 @@ keep_going: /* We will come back to here until there is
goto error_return;
}
- /* We can release the address list now. */
- pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
- conn->addrlist = NULL;
- conn->addr_cur = NULL;
/* Fire up post-connection housekeeping if needed */
if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
@@ -2614,8 +2804,9 @@ keep_going: /* We will come back to here until there is
}
/* Otherwise, we are open for business! */
- conn->status = CONNECTION_OK;
- return PGRES_POLLING_OK;
+ conn->status = CONNECTION_CHECK_RO;
+ goto keep_going;
+
}
case CONNECTION_SETENV:
@@ -2645,9 +2836,101 @@ keep_going: /* We will come back to here until there is
goto error_return;
}
- /* We are open for business! */
+ /*
+ * check if connection is readonly if we need readwrite one
+ */
+ conn->status = CONNECTION_CHECK_RO;
+ goto keep_going;
+
+ case CONNECTION_CHECK_RO:
+
+ /*
+ * consult connection options and check if RO connection is OK
+ * RO connection is OK if readonly connection is explicitely
+ * requested or if replication option is set.
+ */
+ if ((conn->read_only && conn->read_only[0] > '0')
+ ||(conn->replication && conn->replication[0])
+ )
+ {
+ /* We can release the address list now. */
+ pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
+ conn->addrlist = NULL;
+ conn->addr_cur = NULL;
+
+ conn->status = CONNECTION_OK;
+ return PGRES_POLLING_OK;
+ }
+ /* Otherwise request result pg_is_in_recovery() */
+ /* pretend that status is OK for time of sending query */
conn->status = CONNECTION_OK;
- return PGRES_POLLING_OK;
+ PQsendQuery(conn, "SELECT pg_catalog.pg_is_in_recovery()");
+ conn->status = CONNECTION_CHECK_RW;
+ return PGRES_POLLING_READING;
+ case CONNECTION_CHECK_RW:
+ {
+ char *value;
+ PGresult *res;
+
+ conn->status = CONNECTION_OK;
+ if (!PQconsumeInput(conn))
+ {
+ conn->status = CONNECTION_BAD;
+ return PGRES_POLLING_FAILED;
+ }
+ if (PQisBusy(conn))
+ {
+ /* Result is not ready yet */
+ conn->status = CONNECTION_CHECK_RW;
+ return PGRES_POLLING_READING;
+ }
+ res = PQgetResult(conn);
+ /* Call PQgetResult second time to clear connection
+ * state. Should return NULL, so result is ignored
+ */
+ PQgetResult(conn);
+ if (!res || PQresultStatus(res) != PGRES_TUPLES_OK ||
+ PQntuples(res)!=1)
+ {
+ /*
+ * Something wrong happened with this host. skip to next
+ * one
+ */
+ conn->status = CONNECTION_NEEDED;
+ } else {
+ value = PQgetvalue(res, 0, 0);
<<<<<<< BEGIN MERGE CONFLICT: local copy shown first <<<<<<<<<<<<<<<
+ if (value[0] == 't')
======= COMMON ANCESTOR content follows ============================
+ if (strcmp(value, "true") == 0)
======= MERGED IN content follows ==================================
+ if (value[0]=='t')
>>>>>>> END MERGE CONFLICT >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
+ {
+ conn->status = CONNECTION_NEEDED;
+ }
+ }
+ if (res) PQclear(res);
+ if (conn->status != CONNECTION_OK)
+ {
+ ConnStatusType save_status = conn->status;
+
+ conn->status = CONNECTION_OK;
+ pqTerminateConn(conn);
+ pqDropConnection(conn,true);
+ conn->sock = PGINVALID_SOCKET;
+ if (try_next_address(conn))
+ {
+ conn->status = save_status;
+ goto keep_going;
+ }
+ else
+ {
+ conn->status = CONNECTION_BAD;
+ return PGRES_POLLING_FAILED;
+ }
+
+ }
+ /* We can release the address list now. */
+ pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
+ conn->addrlist = NULL;
+ conn->addr_cur = NULL;
+ return PGRES_POLLING_OK;
+ }
default:
appendPQExpBuffer(&conn->errorMessage,
@@ -2936,21 +3219,17 @@ freePGconn(PGconn *conn)
WSACleanup();
#endif
}
-
/*
- * closePGconn
- * - properly close a connection to the backend
+ * pqTerminateConn
+ *
+ * - send terminate message to the backend, but do not free any
+ * transient state of PGconn object, which can be needed to reconnect
*
- * This should reset or release all transient state, but NOT the connection
- * parameters. On exit, the PGconn should be in condition to start a fresh
- * connection with the same parameters (see PQreset()).
*/
-static void
-closePGconn(PGconn *conn)
-{
- PGnotify *notify;
- pgParameterStatus *pstatus;
+
+static void pqTerminateConn(PGconn *conn)
+{
/*
* Note that the protocol doesn't allow us to send Terminate messages
* during the startup phase.
@@ -2966,6 +3245,25 @@ closePGconn(PGconn *conn)
(void) pqFlush(conn);
}
+
+}
+
+/*
+ * closePGconn
+ * - properly close a connection to the backend
+ *
+ * This should reset or release all transient state, but NOT the connection
+ * parameters. On exit, the PGconn should be in condition to start a fresh
+ * connection with the same parameters (see PQreset()).
+ */
+static void
+closePGconn(PGconn *conn)
+{
+ PGnotify *notify;
+ pgParameterStatus *pstatus;
+
+ /* Send terminate request to backend */
+ pqTerminateConn(conn);
/*
* Must reset the blocking status so a possible reconnect will work.
*
@@ -2978,6 +3276,7 @@ closePGconn(PGconn *conn)
* Close the connection, reset all transient state, flush I/O buffers.
*/
pqDropConnection(conn, true);
+
conn->status = CONNECTION_BAD; /* Well, not really _bad_ - just
* absent */
conn->asyncStatus = PGASYNC_IDLE;
@@ -3969,6 +4268,8 @@ parseServiceFile(const char *serviceFile,
{
int linenr = 0,
i;
+ bool hostflag = false; /* true if we already have seen 'host'
+ * parameter in the service file, and */
FILE *f;
char buf[MAXBUFSIZE],
*line;
@@ -4088,7 +4389,29 @@ parseServiceFile(const char *serviceFile,
if (strcmp(options[i].keyword, key) == 0)
{
if (options[i].val == NULL)
+ {
options[i].val = strdup(val);
+ /* Set flag that we get value of host option
+ from this service file, so subsequent
+ host lines should be appended to it,
+ not ignored
+ */
+ if (strcmp(key,"host")==0)
+ hostflag=true;
+ }
+ else if (strcmp(key,"host") == 0 && hostflag)
+ {
+ /* Old host value is from same service file,
+ so append new one to it */
+ char *old=options[i].val;
+ int oldlen=strlen(old);
+ options[i].val=malloc(oldlen+1+strlen(val)+1);
+ strncpy(options[i].val,old,oldlen);
+ options[i].val[oldlen]=',';
+ strcpy(options[i].val+oldlen+1,val);
+ free(old);
+ }
+
if (!options[i].val)
{
printfPQExpBuffer(errorMessage,
@@ -4804,87 +5127,118 @@ conninfo_uri_parse_options(PQconninfoOption *options, const char *uri,
*/
p = start;
}
-
- /*
- * "p" has been incremented past optional URI credential information at
- * this point and now points at the "netloc" part of the URI.
- *
- * Look for IPv6 address.
- */
- if (*p == '[')
- {
- host = ++p;
- while (*p && *p != ']')
- ++p;
- if (!*p)
+ host = p;
+ if (*p==':') {
+ int portnum;
+ char *portstr;
+ *(p++)='\0';
+ portstr = p;
+ portnum = 0;
+ while (*p >= '0' && *p <= '9')
{
- printfPQExpBuffer(errorMessage,
- libpq_gettext("end of string reached when looking for matching \"]\" in IPv6 host address in URI: \"%s\"\n"),
- uri);
- goto cleanup;
+ portnum = portnum * 10 + (*(p++) - '0');
}
- if (p == host)
+ if (portnum > 65535 || portnum <1)
{
printfPQExpBuffer(errorMessage,
- libpq_gettext("IPv6 host address may not be empty in URI: \"%s\"\n"),
- uri);
+ libpq_gettext("invalid port number: \"%d\"\n"),
+ portnum);
goto cleanup;
}
+ prevchar = *p;
+ *p='\0';
+ if (*portstr &&
+ !conninfo_storeval(options, "port", portstr,
+ errorMessage, false, true));
- /* Cut off the bracket and advance */
- *(p++) = '\0';
-
- /*
- * The address may be followed by a port specifier or a slash or a
- * query.
- */
- if (*p && *p != ':' && *p != '/' && *p != '?')
+ } else {
+ do
{
- printfPQExpBuffer(errorMessage,
- libpq_gettext("unexpected character \"%c\" at position %d in URI (expected \":\" or \"/\"): \"%s\"\n"),
- *p, (int) (p - buf + 1), uri);
- goto cleanup;
- }
- }
- else
- {
- /* not an IPv6 address: DNS-named or IPv4 netloc */
- host = p;
-
- /*
- * Look for port specifier (colon) or end of host specifier (slash),
- * or query (question mark).
- */
- while (*p && *p != ':' && *p != '/' && *p != '?')
- ++p;
- }
+ if (*p == ',')
+ p++;
- /* Save the hostname terminator before we null it */
- prevchar = *p;
- *p = '\0';
+ /*
+ * "p" has been incremented past optional URI credential information
+ * at this point and now points at the "netloc" part of the URI.
+ *
+ * Look for IPv6 address.
+ */
+ if (*p == '[')
+ {
+ char *ipv6start = ++p;
- if (*host &&
- !conninfo_storeval(options, "host", host,
- errorMessage, false, true))
- goto cleanup;
+ while (*p && *p != ']')
+ ++p;
+ if (!*p)
+ {
+ printfPQExpBuffer(errorMessage,
+ libpq_gettext("end of string reached when looking for matching \"]\" in IPv6 host address in URI: \"%s\"\n"),
+ uri);
+ goto cleanup;
+ }
+ if (p == ipv6start)
+ {
+ printfPQExpBuffer(errorMessage,
+ libpq_gettext("IPv6 host address may not be empty in URI: \"%s\"\n"),
+ uri);
+ goto cleanup;
+ }
+ p++;
+ /*
+ * The address may be followed by a port specifier, a comma or a
+ * slash or a query.
+ */
+ if (*p && *p != ',' && *p != ':' && *p != '/' && *p != '?')
+ {
+ printfPQExpBuffer(errorMessage,
+ libpq_gettext("unexpected character \"%c\" at position %d in URI (expected \":\" or \"/\"): \"%s\"\n"),
+ *p, (int) (p - buf + 1), uri);
+ goto cleanup;
+ }
- if (prevchar == ':')
- {
- const char *port = ++p; /* advance past host terminator */
+ }
+ else
+ {
+ /* not an IPv6 address: DNS-named or IPv4 netloc */
- while (*p && *p != '/' && *p != '?')
- ++p;
+ /*
+ * Look for port specifier (colon) or end of host specifier
+ * (slash), or query (question mark).
+ */
+ while (*p && *p != ',' && *p != ':' && *p != '/' && *p != '?')
+ ++p;
+ }
+ /* Skip port specifier */
+ if (*p == ':')
+ {
+ int portnum;
+ p++;
+ portnum = 0;
+ while (*p >= '0' && *p <= '9')
+ {
+ portnum = portnum * 10 + (*(p++) - '0');
+ }
+ if (portnum > 65535 || portnum <1)
+ {
+ printfPQExpBuffer(errorMessage,
+ libpq_gettext("invalid port number: \"%d\"\n"),
+ portnum);
+ goto cleanup;
+ }
+ }
+ } while (*p == ',');
+ /* Save the hostname terminator before we null it */
prevchar = *p;
*p = '\0';
-
- if (*port &&
- !conninfo_storeval(options, "port", port,
- errorMessage, false, true))
+
+ if (*host &&
+ !conninfo_storeval(options, "host", host,
+ errorMessage, false, true))
goto cleanup;
- }
+ }
if (prevchar && prevchar != '?')
{
const char *dbname = ++p; /* advance past host terminator */
@@ -5014,6 +5368,16 @@ conninfo_uri_parse_params(char *params,
keyword = "sslmode";
value = "require";
}
+ if ((strcmp(keyword, "loadBalanceHosts") == 0 ||
+ strcmp(keyword, "load_balance_hosts") == 0) &&
+ strcmp(value, "true") == 0)
+ {
+ free(keyword);
+ free(value);
+ malloced = false;
+ keyword = "hostorder";
+ value = "random";
+ }
/*
* Store the value if the corresponding option exists; ignore
@@ -5228,7 +5592,22 @@ conninfo_storeval(PQconninfoOption *connOptions,
}
if (option->val)
+ {
+ if (strcmp(option->keyword, "host") == 0)
+ {
+ /* Accumulate multiple hosts in the single string */
+ int val_len = strlen(option->val),
+ new_len = strlen(value);
+
+ free(value_copy);
+ value_copy = malloc(val_len + 1 + new_len + 1);
+ strncpy(value_copy, option->val, val_len + 1);
+ value_copy[val_len] = ',';
+ strncpy(value_copy + val_len + 1, value, new_len + 1);
+ }
free(option->val);
+
+ }
option->val = value_copy;
return option;
diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index 3a521d4..224db09 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -62,7 +62,11 @@ typedef enum
* backend startup. */
CONNECTION_SETENV, /* Negotiating environment. */
CONNECTION_SSL_STARTUP, /* Negotiating SSL. */
- CONNECTION_NEEDED /* Internal state: connect() needed */
+ CONNECTION_NEEDED, /* Internal state: connect() needed */
+ CONNECTION_CHECK_RO, /* Internal state: need to check is RO
+ * connection acceptable */
+ CONNECTION_CHECK_RW, /* Internal state: waiting that server replies
+ * if it is in recovery */
} ConnStatusType;
typedef enum
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 98ea6b1..dde4db5 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -333,7 +333,11 @@ struct pg_conn
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
char *krbsrvname; /* Kerberos service name */
#endif
-
+ char *hostorder; /* How to handle multiple hosts */
+ char *read_only; /* If true, we could work with readonly
+ * standby server */
+ char *failover_timeout; /* If no usable server found, how long
+ * to wait before retry */
/* Optional file to write trace info to */
FILE *Pfdebug;
@@ -381,10 +385,12 @@ struct pg_conn
struct addrinfo *addrlist; /* list of possible backend addresses */
struct addrinfo *addr_cur; /* the one currently being tried */
int addrlist_family; /* needed to know how to free addrlist */
+ time_t failover_finish_time; /* how long to retry host list
+ *waiting for new master to appear */
PGSetenvStatusType setenv_state; /* for 2.0 protocol only */
const PQEnvironmentOption *next_eo;
bool send_appname; /* okay to send application_name? */
-
+
/* Miscellaneous stuff */
int be_pid; /* PID of backend --- needed for cancels */
int be_key; /* key of backend --- needed for cancels */
diff --git a/src/interfaces/libpq/test/expected.out b/src/interfaces/libpq/test/expected.out
index d375e82..4832bdd 100644
--- a/src/interfaces/libpq/test/expected.out
+++ b/src/interfaces/libpq/test/expected.out
@@ -1,20 +1,20 @@
trying postgresql://uri-user:secret@host:12345/db
-user='uri-user' password='secret' dbname='db' host='host' port='12345' (inet)
+user='uri-user' password='secret' dbname='db' host='host:12345' (inet)
trying postgresql://uri-user@host:12345/db
-user='uri-user' dbname='db' host='host' port='12345' (inet)
+user='uri-user' dbname='db' host='host:12345' (inet)
trying postgresql://uri-user@host/db
user='uri-user' dbname='db' host='host' (inet)
trying postgresql://host:12345/db
-dbname='db' host='host' port='12345' (inet)
+dbname='db' host='host:12345' (inet)
trying postgresql://host/db
dbname='db' host='host' (inet)
trying postgresql://uri-user@host:12345/
-user='uri-user' host='host' port='12345' (inet)
+user='uri-user' host='host:12345' (inet)
trying postgresql://uri-user@host/
user='uri-user' host='host' (inet)
@@ -23,10 +23,10 @@ trying postgresql://uri-user@
user='uri-user' (local)
trying postgresql://host:12345/
-host='host' port='12345' (inet)
+host='host:12345' (inet)
trying postgresql://host:12345
-host='host' port='12345' (inet)
+host='host:12345' (inet)
trying postgresql://host/db
dbname='db' host='host' (inet)
@@ -62,7 +62,7 @@ trying postgresql://host/db?u%7aer=someotheruser&port=12345
uri-regress: invalid URI query parameter: "uzer"
trying postgresql://host:12345?user=uri-user
-user='uri-user' host='host' port='12345' (inet)
+user='uri-user' host='host:12345' (inet)
trying postgresql://host?user=uri-user
user='uri-user' host='host' (inet)
@@ -71,19 +71,19 @@ trying postgresql://host?
host='host' (inet)
trying postgresql://[::1]:12345/db
-dbname='db' host='::1' port='12345' (inet)
+dbname='db' host='[::1]:12345' (inet)
trying postgresql://[::1]/db
-dbname='db' host='::1' (inet)
+dbname='db' host='[::1]' (inet)
trying postgresql://[2001:db8::1234]/
-host='2001:db8::1234' (inet)
+host='[2001:db8::1234]' (inet)
trying postgresql://[200z:db8::1234]/
-host='200z:db8::1234' (inet)
+host='[200z:db8::1234]' (inet)
trying postgresql://[::1]
-host='::1' (inet)
+host='[::1]' (inet)
trying postgres://
(local)
@@ -143,7 +143,7 @@ trying postgres://@host
host='host' (inet)
trying postgres://host:/
-host='host' (inet)
+uri-regress: invalid port number: "0"
trying postgres://:12345/
port='12345' (local)
--
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