On 2015.10.14 at 13:41:51 +0300, Victor Wagner wrote:
>
> Attached patch which implements client library failover and
> loadbalancing as was described in the proposal
> <20150818041850.ga5...@wagner.pp.ru>.
>
I'm sending imporoved verison of patch. As Olexander Shulgin noted,
previous version of patch lacks support for service files.
Now support for service files is implemented and multiple host
statements in the service file are allowed.
--
Victor Wagner <vi...@wagner.pp.ru>
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 0ee018e..ec12fce 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>
@@ -7161,6 +7237,18 @@ 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 f3030fb..29583a7 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -1,5 +1,7 @@
/*-------------------------------------------------------------------------
*
+ UNIXSOCK_PATH(portstr, portnum, conn->pgunixsocket);
+
* fe-connect.c
* functions related to setting up a connection to the backend
*
@@ -114,6 +116,7 @@ static int ldapServiceLookup(const char *purl, PQconninfoOption *options,
#define DefaultSSLMode "disable"
#endif
+
/* ----------
* Definition of the conninfo parameters and their fallback resources.
*
@@ -299,7 +302,16 @@ 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}
@@ -380,6 +392,7 @@ 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;
@@ -1384,11 +1397,17 @@ 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)
@@ -1430,21 +1449,73 @@ 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;
+
+ nodes = malloc(sizeof(struct nodeinfo) * 4);
+ while (*p)
+ {
+ q = p;
+ r = NULL;
+ 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)
+ {
+ 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--;
+ }
+ 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;
+ }
+ 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)
@@ -1454,33 +1525,73 @@ 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)
+ /* loop over all the host specs in the node variable */
+ for (node = nodes; node->host != NULL || node->port != NULL; node++)
{
- if (node)
- appendPQExpBuffer(&conn->errorMessage,
- libpq_gettext("could not translate host name \"%s\" to address: %s\n"),
- node, gai_strerror(ret));
+ struct addrinfo *this_node_addrs;
+
+ 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 */
+ 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" */
@@ -1493,12 +1604,23 @@ 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
@@ -1597,6 +1719,76 @@ 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
*
@@ -1674,7 +1866,8 @@ PQconnectPoll(PGconn *conn)
case CONNECTION_SSL_STARTUP:
case CONNECTION_NEEDED:
break;
-
+ case CONNECTION_CHECK_RW:
+ break;
default:
appendPQExpBufferStr(&conn->errorMessage,
libpq_gettext(
@@ -1712,9 +1905,8 @@ 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,
@@ -1733,7 +1925,7 @@ keep_going: /* We will come back to here until there is
if (!connectNoDelay(conn))
{
pqDropConnection(conn);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
}
@@ -1743,7 +1935,7 @@ 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);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
@@ -1754,7 +1946,7 @@ 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);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
#endif /* F_SETFD */
@@ -1801,7 +1993,7 @@ keep_going: /* We will come back to here until there is
if (err)
{
pqDropConnection(conn);
- conn->addr_cur = addr_cur->ai_next;
+ try_next_address(conn);
continue;
}
}
@@ -1892,7 +2084,7 @@ 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 */
/*
@@ -1938,9 +2130,8 @@ 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;
}
@@ -2608,8 +2799,9 @@ 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:
@@ -2639,9 +2831,81 @@ keep_going: /* We will come back to here until there is
goto error_return;
}
- /* We are open for business! */
+ /*
+ * check if connectionV 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
+ */
+ if (conn->read_only && conn->read_only[0] > '0')
+ {
+ 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_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);
+ if (PQresultStatus(res) != PGRES_TUPLES_OK)
+ {
+ /*
+ * Something wrong happened with this host. skip to next
+ * one
+ */
+ conn->status = CONNECTION_NEEDED;
+ }
+ value = PQgetvalue(res, 0, 0);
+ if (strcmp(value, "true") == 0)
+ {
+ conn->status = CONNECTION_NEEDED;
+ }
+ PQclear(res);
+ if (conn->status != CONNECTION_OK)
+ {
+ ConnStatusType save_status = conn->status;
+
+ conn->status = CONNECTION_OK;
+ closePGconn(conn);
+ 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;
+ }
+
+ }
+ return PGRES_POLLING_OK;
+ }
default:
appendPQExpBuffer(&conn->errorMessage,
@@ -3963,6 +4227,8 @@ 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;
@@ -4081,8 +4347,30 @@ parseServiceFile(const char *serviceFile,
{
if (strcmp(options[i].keyword, key) == 0)
{
- if (options[i].val == NULL)
+ 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,
@@ -4798,87 +5086,118 @@ 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 */
@@ -5008,6 +5327,16 @@ 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
@@ -5222,7 +5551,22 @@ 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 828c533..20899bc 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 04d056e..164c858 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -334,7 +334,11 @@ 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;
@@ -382,10 +386,12 @@ 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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