{"target_session_attrs", "PGTARGETSESSIONATTRS",
DefaultTargetSessionAttrs, NULL,
- "Target-Session-Attrs", "", 11, /* sizeof("read-write") = 11 */
+ "Target-Session-Attrs", "", 15, /* sizeof("prefer-standby") = 15 */
offsetof(struct pg_conn, target_session_attrs)},
/* Terminating entry --- MUST BE LAST */
conn->pstatus = NULL;
conn->client_encoding = PG_SQL_ASCII;
conn->std_strings = false;
+ conn->default_transaction_read_only = PG_BOOL_UNKNOWN;
+ conn->in_hot_standby = PG_BOOL_UNKNOWN;
conn->sversion = 0;
/* Drop large-object lookup data */
}
/*
- * Resolve special "auto" client_encoding from the locale
- */
- if (conn->client_encoding_initial &&
- strcmp(conn->client_encoding_initial, "auto") == 0)
- {
- free(conn->client_encoding_initial);
- conn->client_encoding_initial = strdup(pg_encoding_to_char(pg_get_encoding_from_locale(NULL, true)));
- if (!conn->client_encoding_initial)
- goto oom_error;
- }
-
- /*
- * Validate target_session_attrs option.
+ * validate target_session_attrs option, and set target_server_type
*/
if (conn->target_session_attrs)
{
- if (strcmp(conn->target_session_attrs, "any") != 0
- && strcmp(conn->target_session_attrs, "read-write") != 0)
+ if (strcmp(conn->target_session_attrs, "any") == 0)
+ conn->target_server_type = SERVER_TYPE_ANY;
+ else if (strcmp(conn->target_session_attrs, "read-write") == 0)
+ conn->target_server_type = SERVER_TYPE_READ_WRITE;
+ else if (strcmp(conn->target_session_attrs, "read-only") == 0)
+ conn->target_server_type = SERVER_TYPE_READ_ONLY;
+ else if (strcmp(conn->target_session_attrs, "primary") == 0)
+ conn->target_server_type = SERVER_TYPE_PRIMARY;
+ else if (strcmp(conn->target_session_attrs, "standby") == 0)
+ conn->target_server_type = SERVER_TYPE_STANDBY;
+ else if (strcmp(conn->target_session_attrs, "prefer-standby") == 0)
+ conn->target_server_type = SERVER_TYPE_PREFER_STANDBY;
+ else
{
conn->status = CONNECTION_BAD;
appendPQExpBuffer(&conn->errorMessage,
libpq_gettext("invalid %s value: \"%s\"\n"),
- "target_settion_attrs",
+ "target_session_attrs",
conn->target_session_attrs);
return false;
}
}
+ else
+ conn->target_server_type = SERVER_TYPE_ANY;
+
+ /*
+ * Resolve special "auto" client_encoding from the locale
+ */
+ if (conn->client_encoding_initial &&
+ strcmp(conn->client_encoding_initial, "auto") == 0)
+ {
+ free(conn->client_encoding_initial);
+ conn->client_encoding_initial = strdup(pg_encoding_to_char(pg_get_encoding_from_locale(NULL, true)));
+ if (!conn->client_encoding_initial)
+ goto oom_error;
+ }
/*
* Only if we get this far is it appropriate to try to connect. (We need a
conn->try_next_host = true;
conn->status = CONNECTION_NEEDED;
+ /* Also reset the target_server_type state if needed */
+ if (conn->target_server_type == SERVER_TYPE_PREFER_STANDBY_PASS2)
+ conn->target_server_type = SERVER_TYPE_PREFER_STANDBY;
+
/*
* The code for processing CONNECTION_NEEDED state is in PQconnectPoll(),
* so that it can easily be re-executed if needed again during the
/* These are reading states */
case CONNECTION_AWAITING_RESPONSE:
case CONNECTION_AUTH_OK:
+ case CONNECTION_CHECK_WRITABLE:
+ case CONNECTION_CONSUME:
+ case CONNECTION_CHECK_STANDBY:
{
/* Load waiting data */
int n = pqReadData(conn);
/* Special cases: proceed without waiting. */
case CONNECTION_SSL_STARTUP:
case CONNECTION_NEEDED:
- case CONNECTION_CHECK_WRITABLE:
- case CONNECTION_CONSUME:
case CONNECTION_GSS_STARTUP:
+ case CONNECTION_CHECK_TARGET:
break;
default:
int ret;
char portstr[MAXPGPATH];
- if (conn->whichhost + 1 >= conn->nconnhost)
+ if (conn->whichhost + 1 < conn->nconnhost)
+ conn->whichhost++;
+ else
{
/*
- * Oops, no more hosts. An appropriate error message is already
- * set up, so just set the right status.
+ * Oops, no more hosts.
+ *
+ * If we are trying to connect in "prefer-standby" mode, then drop
+ * the standby requirement and start over.
+ *
+ * Otherwise, an appropriate error message is already set up, so
+ * we just need to set the right status.
*/
- goto error_return;
+ if (conn->target_server_type == SERVER_TYPE_PREFER_STANDBY &&
+ conn->nconnhost > 0)
+ {
+ conn->target_server_type = SERVER_TYPE_PREFER_STANDBY_PASS2;
+ conn->whichhost = 0;
+ }
+ else
+ goto error_return;
}
- conn->whichhost++;
/* Drop any address info for previous host */
release_conn_addrinfo(conn);
case CONNECTION_CHECK_TARGET:
{
/*
- * If a read-write connection is required, see if we have one.
- *
- * Servers before 7.4 lack the transaction_read_only GUC, but
- * by the same token they don't have any read-only mode, so we
- * may just skip the test in that case.
+ * If a read-write, read-only, primary, or standby connection
+ * is required, see if we have one.
*/
- if (conn->sversion >= 70400 &&
- conn->target_session_attrs != NULL &&
- strcmp(conn->target_session_attrs, "read-write") == 0)
+ if (conn->target_server_type == SERVER_TYPE_READ_WRITE ||
+ conn->target_server_type == SERVER_TYPE_READ_ONLY)
{
+ bool read_only_server;
+
/*
- * We use PQsendQueryContinue so that conn->errorMessage
- * does not get cleared. We need to preserve any error
- * messages related to previous hosts we have tried and
- * failed to connect to.
+ * If the server didn't report
+ * "default_transaction_read_only" or "in_hot_standby" at
+ * startup, we must determine its state by sending the
+ * query "SHOW transaction_read_only". Servers before 7.4
+ * lack the transaction_read_only GUC, but by the same
+ * token they don't have any read-only mode, so we may
+ * just assume the results.
*/
- conn->status = CONNECTION_OK;
- if (!PQsendQueryContinue(conn,
- "SHOW transaction_read_only"))
- goto error_return;
- conn->status = CONNECTION_CHECK_WRITABLE;
- return PGRES_POLLING_READING;
+ if (conn->sversion < 70400)
+ {
+ conn->default_transaction_read_only = PG_BOOL_NO;
+ conn->in_hot_standby = PG_BOOL_NO;
+ }
+
+ if (conn->default_transaction_read_only == PG_BOOL_UNKNOWN ||
+ conn->in_hot_standby == PG_BOOL_UNKNOWN)
+ {
+ /*
+ * We use PQsendQueryContinue so that
+ * conn->errorMessage does not get cleared. We need
+ * to preserve any error messages related to previous
+ * hosts we have tried and failed to connect to.
+ */
+ conn->status = CONNECTION_OK;
+ if (!PQsendQueryContinue(conn,
+ "SHOW transaction_read_only"))
+ goto error_return;
+ /* We'll return to this state when we have the answer */
+ conn->status = CONNECTION_CHECK_WRITABLE;
+ return PGRES_POLLING_READING;
+ }
+
+ /* OK, we can make the test */
+ read_only_server =
+ (conn->default_transaction_read_only == PG_BOOL_YES ||
+ conn->in_hot_standby == PG_BOOL_YES);
+
+ if ((conn->target_server_type == SERVER_TYPE_READ_WRITE) ?
+ read_only_server : !read_only_server)
+ {
+ /* Wrong server state, reject and try the next host */
+ if (conn->target_server_type == SERVER_TYPE_READ_WRITE)
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("session is read-only\n"));
+ else
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("session is not read-only\n"));
+
+ /* Close connection politely. */
+ conn->status = CONNECTION_OK;
+ sendTerminateConn(conn);
+
+ /*
+ * Try next host if any, but we don't want to consider
+ * additional addresses for this host.
+ */
+ conn->try_next_host = true;
+ goto keep_going;
+ }
+ }
+ else if (conn->target_server_type == SERVER_TYPE_PRIMARY ||
+ conn->target_server_type == SERVER_TYPE_STANDBY ||
+ conn->target_server_type == SERVER_TYPE_PREFER_STANDBY)
+ {
+ /*
+ * If the server didn't report "in_hot_standby" at
+ * startup, we must determine its state by sending the
+ * query "SELECT pg_catalog.pg_is_in_recovery()". Servers
+ * before 9.0 don't have that function, but by the same
+ * token they don't have any standby mode, so we may just
+ * assume the result.
+ */
+ if (conn->sversion < 90000)
+ conn->in_hot_standby = PG_BOOL_NO;
+
+ if (conn->in_hot_standby == PG_BOOL_UNKNOWN)
+ {
+ /*
+ * We use PQsendQueryContinue so that
+ * conn->errorMessage does not get cleared. We need
+ * to preserve any error messages related to previous
+ * hosts we have tried and failed to connect to.
+ */
+ conn->status = CONNECTION_OK;
+ if (!PQsendQueryContinue(conn,
+ "SELECT pg_catalog.pg_is_in_recovery()"))
+ goto error_return;
+ /* We'll return to this state when we have the answer */
+ conn->status = CONNECTION_CHECK_STANDBY;
+ return PGRES_POLLING_READING;
+ }
+
+ /* OK, we can make the test */
+ if ((conn->target_server_type == SERVER_TYPE_PRIMARY) ?
+ (conn->in_hot_standby == PG_BOOL_YES) :
+ (conn->in_hot_standby == PG_BOOL_NO))
+ {
+ /* Wrong server state, reject and try the next host */
+ if (conn->target_server_type == SERVER_TYPE_PRIMARY)
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("server is in hot standby mode\n"));
+ else
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("server is not in hot standby mode\n"));
+
+ /* Close connection politely. */
+ conn->status = CONNECTION_OK;
+ sendTerminateConn(conn);
+
+ /*
+ * Try next host if any, but we don't want to consider
+ * additional addresses for this host.
+ */
+ conn->try_next_host = true;
+ goto keep_going;
+ }
}
/* We can release the address list now. */
case CONNECTION_CONSUME:
{
+ /*
+ * This state just makes sure the connection is idle after
+ * we've obtained the result of a SHOW or SELECT query. Once
+ * we're clear, return to CONNECTION_CHECK_TARGET state to
+ * decide what to do next. We must transiently set status =
+ * CONNECTION_OK in order to use the result-consuming
+ * subroutines.
+ */
conn->status = CONNECTION_OK;
if (!PQconsumeInput(conn))
goto error_return;
return PGRES_POLLING_READING;
}
- /*
- * Call PQgetResult() again to consume NULL result.
- */
+ /* Call PQgetResult() again until we get a NULL result */
res = PQgetResult(conn);
if (res != NULL)
{
PQclear(res);
conn->status = CONNECTION_CONSUME;
- goto keep_going;
+ return PGRES_POLLING_READING;
}
- /* We can release the address list now. */
- release_conn_addrinfo(conn);
-
- /* We are open for business! */
- conn->status = CONNECTION_OK;
- return PGRES_POLLING_OK;
+ conn->status = CONNECTION_CHECK_TARGET;
+ goto keep_going;
}
+
case CONNECTION_CHECK_WRITABLE:
{
+ /*
+ * Waiting for result of "SHOW transaction_read_only". We
+ * must transiently set status = CONNECTION_OK in order to use
+ * the result-consuming subroutines.
+ */
conn->status = CONNECTION_OK;
if (!PQconsumeInput(conn))
goto error_return;
}
res = PQgetResult(conn);
- if (res && (PQresultStatus(res) == PGRES_TUPLES_OK) &&
+ if (res && PQresultStatus(res) == PGRES_TUPLES_OK &&
PQntuples(res) == 1)
{
- char *val;
+ char *val = PQgetvalue(res, 0, 0);
- val = PQgetvalue(res, 0, 0);
+ /*
+ * "transaction_read_only = on" proves that at least one
+ * of default_transaction_read_only and in_hot_standby is
+ * on, but we don't actually know which. We don't care
+ * though for the purpose of identifying a read-only
+ * session, so satisfy the CONNECTION_CHECK_TARGET code by
+ * claiming they are both on. On the other hand, if it's
+ * a read-write session, they are certainly both off.
+ */
if (strncmp(val, "on", 2) == 0)
{
- /* Not writable; fail this connection. */
- PQclear(res);
+ conn->default_transaction_read_only = PG_BOOL_YES;
+ conn->in_hot_standby = PG_BOOL_YES;
+ }
+ else
+ {
+ conn->default_transaction_read_only = PG_BOOL_NO;
+ conn->in_hot_standby = PG_BOOL_NO;
+ }
+ PQclear(res);
- /* Append error report to conn->errorMessage. */
- appendPQExpBufferStr(&conn->errorMessage,
- libpq_gettext("session is read-only\n"));
+ /* Finish reading messages before continuing */
+ conn->status = CONNECTION_CONSUME;
+ goto keep_going;
+ }
- /* Close connection politely. */
- conn->status = CONNECTION_OK;
- sendTerminateConn(conn);
+ /* Something went wrong with "SHOW transaction_read_only". */
+ if (res)
+ PQclear(res);
- /*
- * Try next host if any, but we don't want to consider
- * additional addresses for this host.
- */
- conn->try_next_host = true;
- goto keep_going;
- }
+ /* Append error report to conn->errorMessage. */
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("\"SHOW transaction_read_only\" failed\n"));
+
+ /* Close connection politely. */
+ conn->status = CONNECTION_OK;
+ sendTerminateConn(conn);
+
+ /* Try next host. */
+ conn->try_next_host = true;
+ goto keep_going;
+ }
- /* Session is read-write, so we're good. */
+ case CONNECTION_CHECK_STANDBY:
+ {
+ /*
+ * Waiting for result of "SELECT pg_is_in_recovery()". We
+ * must transiently set status = CONNECTION_OK in order to use
+ * the result-consuming subroutines.
+ */
+ conn->status = CONNECTION_OK;
+ if (!PQconsumeInput(conn))
+ goto error_return;
+
+ if (PQisBusy(conn))
+ {
+ conn->status = CONNECTION_CHECK_STANDBY;
+ return PGRES_POLLING_READING;
+ }
+
+ res = PQgetResult(conn);
+ if (res && PQresultStatus(res) == PGRES_TUPLES_OK &&
+ PQntuples(res) == 1)
+ {
+ char *val = PQgetvalue(res, 0, 0);
+
+ if (strncmp(val, "t", 1) == 0)
+ conn->in_hot_standby = PG_BOOL_YES;
+ else
+ conn->in_hot_standby = PG_BOOL_NO;
PQclear(res);
- /*
- * Finish reading any remaining messages before being
- * considered as ready.
- */
+ /* Finish reading messages before continuing */
conn->status = CONNECTION_CONSUME;
goto keep_going;
}
- /*
- * Something went wrong with "SHOW transaction_read_only". We
- * should try next addresses.
- */
+ /* Something went wrong with "SELECT pg_is_in_recovery()". */
if (res)
PQclear(res);
/* Append error report to conn->errorMessage. */
appendPQExpBufferStr(&conn->errorMessage,
- libpq_gettext("test \"SHOW transaction_read_only\" failed\n"));
+ libpq_gettext("\"SELECT pg_is_in_recovery()\" failed\n"));
/* Close connection politely. */
conn->status = CONNECTION_OK;
sendTerminateConn(conn);
- /* Try next address */
- conn->try_next_addr = true;
+ /* Try next host. */
+ conn->try_next_host = true;
goto keep_going;
}
conn->setenv_state = SETENV_STATE_IDLE;
conn->client_encoding = PG_SQL_ASCII;
conn->std_strings = false; /* unless server says differently */
+ conn->default_transaction_read_only = PG_BOOL_UNKNOWN;
+ conn->in_hot_standby = PG_BOOL_UNKNOWN;
conn->verbosity = PQERRORS_DEFAULT;
conn->show_context = PQSHOW_CONTEXT_ERRORS;
conn->sock = PGINVALID_SOCKET;
use warnings;
use PostgresNode;
use TestLib;
-use Test::More tests => 36;
+use Test::More tests => 49;
# Initialize primary node
my $node_primary = get_new_node('primary');
my $node2_port = $node2->port;
my $node2_name = $node2->name;
- my $target_name = $target_node->name;
+ my $target_name = $target_node->name if (defined $target_node);
# Build connection string for connection attempt.
my $connstr = "host=$node1_host,$node2_host ";
my ($ret, $stdout, $stderr) =
$node1->psql('postgres', 'SHOW port;',
extra_params => [ '-d', $connstr ]);
- is( $status == $ret && $stdout eq $target_node->port,
- 1,
- "connect to node $target_name if mode \"$mode\" and $node1_name,$node2_name listed"
- );
+ if ($status == 0)
+ {
+ is( $status == $ret && $stdout eq $target_node->port,
+ 1,
+ "connect to node $target_name if mode \"$mode\" and $node1_name,$node2_name listed"
+ );
+ }
+ else
+ {
+ print "status = $status\n";
+ print "ret = $ret\n";
+ print "stdout = $stdout\n";
+ print "stderr = $stderr\n";
+
+ is( $status == $ret,
+ 1,
+ "fail to connect to any nodes if mode \"$mode\" and $node1_name,$node2_name listed"
+ );
+ }
return;
}
"read-write", 0);
# Connect to primary in "any" mode with primary,standby1 list.
-test_target_session_attrs($node_primary, $node_standby_1, $node_primary, "any",
- 0);
+test_target_session_attrs($node_primary, $node_standby_1, $node_primary,
+ "any", 0);
# Connect to standby1 in "any" mode with standby1,primary list.
test_target_session_attrs($node_standby_1, $node_primary, $node_standby_1,
"any", 0);
+# Connect to primary in "primary" mode with primary,standby1 list.
+test_target_session_attrs($node_primary, $node_standby_1, $node_primary,
+ "primary", 0);
+
+# Connect to primary in "primary" mode with standby1,primary list.
+test_target_session_attrs($node_standby_1, $node_primary, $node_primary,
+ "primary", 0);
+
+# Connect to standby1 in "read-only" mode with primary,standby1 list.
+test_target_session_attrs($node_primary, $node_standby_1, $node_standby_1,
+ "read-only", 0);
+
+# Connect to standby1 in "read-only" mode with standby1,primary list.
+test_target_session_attrs($node_standby_1, $node_primary, $node_standby_1,
+ "read-only", 0);
+
+# Connect to primary in "prefer-standby" mode with primary,primary list.
+test_target_session_attrs($node_primary, $node_primary, $node_primary,
+ "prefer-standby", 0);
+
+# Connect to standby1 in "prefer-standby" mode with primary,standby1 list.
+test_target_session_attrs($node_primary, $node_standby_1, $node_standby_1,
+ "prefer-standby", 0);
+
+# Connect to standby1 in "prefer-standby" mode with standby1,primary list.
+test_target_session_attrs($node_standby_1, $node_primary, $node_standby_1,
+ "prefer-standby", 0);
+
+# Connect to standby1 in "standby" mode with primary,standby1 list.
+test_target_session_attrs($node_primary, $node_standby_1, $node_standby_1,
+ "standby", 0);
+
+# Connect to standby1 in "standby" mode with standby1,primary list.
+test_target_session_attrs($node_standby_1, $node_primary, $node_standby_1,
+ "standby", 0);
+
+# Fail to connect in "read-write" mode with standby1,standby2 list.
+test_target_session_attrs($node_standby_1, $node_standby_2, undef,
+ "read-write", 2);
+
+# Fail to connect in "primary" mode with standby1,standby2 list.
+test_target_session_attrs($node_standby_1, $node_standby_2, undef,
+ "primary", 2);
+
+# Fail to connect in "read-only" mode with primary,primary list.
+test_target_session_attrs($node_primary, $node_primary, undef,
+ "read-only", 2);
+
+# Fail to connect in "standby" mode with primary,primary list.
+test_target_session_attrs($node_primary, $node_primary, undef, "standby", 2);
+
# Test for SHOW commands using a WAL sender connection with a replication
# role.
note "testing SHOW commands for replication connection";
projects / users / c2main / postgres.git / commitdiff