Add support for temporary replication slots
authorPeter Eisentraut <peter_e@gmx.net>
Thu, 8 Dec 2016 17:00:00 +0000 (12:00 -0500)
committerPeter Eisentraut <peter_e@gmx.net>
Mon, 12 Dec 2016 13:38:17 +0000 (08:38 -0500)
This allows creating temporary replication slots that are removed
automatically at the end of the session or on error.

From: Petr Jelinek <petr.jelinek@2ndquadrant.com>

18 files changed:
contrib/test_decoding/Makefile
contrib/test_decoding/expected/ddl.out
contrib/test_decoding/expected/slot.out [new file with mode: 0644]
contrib/test_decoding/sql/slot.sql [new file with mode: 0644]
doc/src/sgml/func.sgml
doc/src/sgml/protocol.sgml
src/backend/catalog/system_views.sql
src/backend/replication/repl_gram.y
src/backend/replication/repl_scanner.l
src/backend/replication/slot.c
src/backend/replication/slotfuncs.c
src/backend/replication/walsender.c
src/backend/storage/lmgr/proc.c
src/backend/tcop/postgres.c
src/include/catalog/pg_proc.h
src/include/nodes/replnodes.h
src/include/replication/slot.h
src/test/regress/expected/rules.out

index a6641f5040d5efc9e42f265054c58ab8c66baf5d..d2bc8b8350a43b5c83c313f153cf7f6d208be92e 100644 (file)
@@ -39,7 +39,7 @@ submake-test_decoding:
 
 REGRESSCHECKS=ddl xact rewrite toast permissions decoding_in_xact \
    decoding_into_rel binary prepared replorigin time messages \
-   spill
+   spill slot
 
 regresscheck: | submake-regress submake-test_decoding temp-install
    $(MKDIR_P) regression_output
index a9ba615b5bbd42dd3cb377ad472f6f65613fc9b3..c104c4802d1c4e195148dc44c27e7c70790a3db0 100644 (file)
@@ -702,7 +702,7 @@ SELECT pg_drop_replication_slot('regression_slot');
 
 /* check that the slot is gone */
 SELECT * FROM pg_replication_slots;
- slot_name | plugin | slot_type | datoid | database | active | active_pid | xmin | catalog_xmin | restart_lsn | confirmed_flush_lsn 
------------+--------+-----------+--------+----------+--------+------------+------+--------------+-------------+---------------------
+ slot_name | plugin | slot_type | datoid | database | temporary | active | active_pid | xmin | catalog_xmin | restart_lsn | confirmed_flush_lsn 
+-----------+--------+-----------+--------+----------+-----------+--------+------------+------+--------------+-------------+---------------------
 (0 rows)
 
diff --git a/contrib/test_decoding/expected/slot.out b/contrib/test_decoding/expected/slot.out
new file mode 100644 (file)
index 0000000..5e6b70b
--- /dev/null
@@ -0,0 +1,58 @@
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding');
+ ?column? 
+----------
+ init
+(1 row)
+
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_t', 'test_decoding', true);
+ ?column? 
+----------
+ init
+(1 row)
+
+SELECT pg_drop_replication_slot('regression_slot_p');
+ pg_drop_replication_slot 
+--------------------------
+(1 row)
+
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding', false);
+ ?column? 
+----------
+ init
+(1 row)
+
+-- reconnect to clean temp slots
+\c
+SELECT pg_drop_replication_slot('regression_slot_p');
+ pg_drop_replication_slot 
+--------------------------
+(1 row)
+
+-- should fail because the temporary slot was dropped automatically
+SELECT pg_drop_replication_slot('regression_slot_t');
+ERROR:  replication slot "regression_slot_t" does not exist
+-- test switching between slots in a session
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot1', 'test_decoding', true);
+ ?column? 
+----------
+ init
+(1 row)
+
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot2', 'test_decoding', true);
+ ?column? 
+----------
+ init
+(1 row)
+
+SELECT * FROM pg_logical_slot_get_changes('regression_slot1', NULL, NULL);
+ location | xid | data 
+----------+-----+------
+(0 rows)
+
+SELECT * FROM pg_logical_slot_get_changes('regression_slot2', NULL, NULL);
+ location | xid | data 
+----------+-----+------
+(0 rows)
+
diff --git a/contrib/test_decoding/sql/slot.sql b/contrib/test_decoding/sql/slot.sql
new file mode 100644 (file)
index 0000000..3b0aecd
--- /dev/null
@@ -0,0 +1,20 @@
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding');
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_t', 'test_decoding', true);
+
+SELECT pg_drop_replication_slot('regression_slot_p');
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding', false);
+
+-- reconnect to clean temp slots
+\c
+
+SELECT pg_drop_replication_slot('regression_slot_p');
+
+-- should fail because the temporary slot was dropped automatically
+SELECT pg_drop_replication_slot('regression_slot_t');
+
+
+-- test switching between slots in a session
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot1', 'test_decoding', true);
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot2', 'test_decoding', true);
+SELECT * FROM pg_logical_slot_get_changes('regression_slot1', NULL, NULL);
+SELECT * FROM pg_logical_slot_get_changes('regression_slot2', NULL, NULL);
index eca98dfd349b54bfdf8b78d929c5d78d0f0f1c48..0f9c9bf1296785992b24db1d340d1364e96483b6 100644 (file)
@@ -18465,7 +18465,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         <indexterm>
          <primary>pg_create_physical_replication_slot</primary>
         </indexterm>
-        <literal><function>pg_create_physical_replication_slot(<parameter>slot_name</parameter> <type>name</type> <optional>, <parameter>immediately_reserve</> <type>boolean</> </optional>)</function></literal>
+        <literal><function>pg_create_physical_replication_slot(<parameter>slot_name</parameter> <type>name</type> <optional>, <parameter>immediately_reserve</> <type>boolean</>, <parameter>temporary</> <type>boolean</></optional>)</function></literal>
        </entry>
        <entry>
         (<parameter>slot_name</parameter> <type>name</type>, <parameter>xlog_position</parameter> <type>pg_lsn</type>)
@@ -18478,7 +18478,11 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         the <acronym>LSN</> is reserved on first connection from a streaming
         replication client. Streaming changes from a physical slot is only
         possible with the streaming-replication protocol &mdash;
-        see <xref linkend="protocol-replication">. This function corresponds
+        see <xref linkend="protocol-replication">. The optional third
+        parameter, <parameter>temporary</>, when set to true, specifies that
+        the slot should not be permanently stored to disk and is only meant
+        for use by current session. Temporary slots are also
+        released upon any error. This function corresponds
         to the replication protocol command <literal>CREATE_REPLICATION_SLOT
         ... PHYSICAL</literal>.
        </entry>
@@ -18505,7 +18509,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         <indexterm>
          <primary>pg_create_logical_replication_slot</primary>
         </indexterm>
-        <literal><function>pg_create_logical_replication_slot(<parameter>slot_name</parameter> <type>name</type>, <parameter>plugin</parameter> <type>name</type>)</function></literal>
+        <literal><function>pg_create_logical_replication_slot(<parameter>slot_name</parameter> <type>name</type>, <parameter>plugin</parameter> <type>name</type> <optional>, <parameter>temporary</> <type>boolean</></optional>)</function></literal>
        </entry>
        <entry>
         (<parameter>slot_name</parameter> <type>name</type>, <parameter>xlog_position</parameter> <type>pg_lsn</type>)
@@ -18513,7 +18517,11 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
        <entry>
         Creates a new logical (decoding) replication slot named
         <parameter>slot_name</parameter> using the output plugin
-        <parameter>plugin</parameter>.  A call to this function has the same
+        <parameter>plugin</parameter>. The optional third
+        parameter, <parameter>temporary</>, when set to true, specifies that
+        the slot should not be permanently stored to disk and is only meant
+        for use by current session. Temporary slots are also
+        released upon any error. A call to this function has the same
         effect as the replication protocol command
         <literal>CREATE_REPLICATION_SLOT ... LOGICAL</literal>.
        </entry>
index 50cf52742745ccc292c88e6f0660562c6b042275..9ba147cae5e7917e06fdc11ad92ae905ce17fee2 100644 (file)
@@ -1434,7 +1434,7 @@ The commands accepted in walsender mode are:
   </varlistentry>
 
   <varlistentry>
-   <term><literal>CREATE_REPLICATION_SLOT</literal> <replaceable class="parameter">slot_name</> { <literal>PHYSICAL</> [ <literal>RESERVE_WAL</> ] | <literal>LOGICAL</> <replaceable class="parameter">output_plugin</> }
+   <term><literal>CREATE_REPLICATION_SLOT</literal> <replaceable class="parameter">slot_name</> [ <literal>TEMPORARY</> ] { <literal>PHYSICAL</> [ <literal>RESERVE_WAL</> ] | <literal>LOGICAL</> <replaceable class="parameter">output_plugin</> }
      <indexterm><primary>CREATE_REPLICATION_SLOT</primary></indexterm>
     </term>
     <listitem>
@@ -1464,6 +1464,17 @@ The commands accepted in walsender mode are:
        </listitem>
       </varlistentry>
 
+      <varlistentry>
+       <term><literal>TEMPORARY</></term>
+       <listitem>
+        <para>
+         Specify that this replication slot is a temporary one. Temporary
+         slots are not saved to disk and are automatically dropped on error
+         or when the session has finished.
+        </para>
+       </listitem>
+      </varlistentry>
+
       <varlistentry>
        <term><literal>RESERVE_WAL</></term>
        <listitem>
index df59d1819caa0acdb43717b576b8e71cbb8eff7e..48e7c4b7f956b8fa63f12470fa7685057ce30158 100644 (file)
@@ -726,6 +726,7 @@ CREATE VIEW pg_replication_slots AS
             L.slot_type,
             L.datoid,
             D.datname AS database,
+            L.temporary,
             L.active,
             L.active_pid,
             L.xmin,
@@ -991,12 +992,22 @@ AS 'pg_logical_slot_peek_binary_changes';
 
 CREATE OR REPLACE FUNCTION pg_create_physical_replication_slot(
     IN slot_name name, IN immediately_reserve boolean DEFAULT false,
+    IN temporary boolean DEFAULT false,
     OUT slot_name name, OUT xlog_position pg_lsn)
 RETURNS RECORD
 LANGUAGE INTERNAL
 STRICT VOLATILE
 AS 'pg_create_physical_replication_slot';
 
+CREATE OR REPLACE FUNCTION pg_create_logical_replication_slot(
+    IN slot_name name, IN plugin name,
+    IN temporary boolean DEFAULT false,
+    OUT slot_name text, OUT xlog_position pg_lsn)
+RETURNS RECORD
+LANGUAGE INTERNAL
+STRICT VOLATILE
+AS 'pg_create_logical_replication_slot';
+
 CREATE OR REPLACE FUNCTION
   make_interval(years int4 DEFAULT 0, months int4 DEFAULT 0, weeks int4 DEFAULT 0,
                 days int4 DEFAULT 0, hours int4 DEFAULT 0, mins int4 DEFAULT 0,
index fd0fa6dde08631ac92a52ab34ccdf10d898e31c5..e75516c8d2574925b01d71de600f42e2014bd09f 100644 (file)
@@ -77,6 +77,7 @@ Node *replication_parse_result;
 %token K_LOGICAL
 %token K_SLOT
 %token K_RESERVE_WAL
+%token K_TEMPORARY
 
 %type <node>   command
 %type <node>   base_backup start_replication start_logical_replication
@@ -89,7 +90,7 @@ Node *replication_parse_result;
 %type <defelt> plugin_opt_elem
 %type <node>   plugin_opt_arg
 %type <str>        opt_slot
-%type <boolval>    opt_reserve_wal
+%type <boolval>    opt_reserve_wal opt_temporary
 
 %%
 
@@ -183,24 +184,26 @@ base_backup_opt:
            ;
 
 create_replication_slot:
-           /* CREATE_REPLICATION_SLOT slot PHYSICAL RESERVE_WAL */
-           K_CREATE_REPLICATION_SLOT IDENT K_PHYSICAL opt_reserve_wal
+           /* CREATE_REPLICATION_SLOT slot TEMPORARY PHYSICAL RESERVE_WAL */
+           K_CREATE_REPLICATION_SLOT IDENT opt_temporary K_PHYSICAL opt_reserve_wal
                {
                    CreateReplicationSlotCmd *cmd;
                    cmd = makeNode(CreateReplicationSlotCmd);
                    cmd->kind = REPLICATION_KIND_PHYSICAL;
                    cmd->slotname = $2;
-                   cmd->reserve_wal = $4;
+                   cmd->temporary = $3;
+                   cmd->reserve_wal = $5;
                    $$ = (Node *) cmd;
                }
-           /* CREATE_REPLICATION_SLOT slot LOGICAL plugin */
-           | K_CREATE_REPLICATION_SLOT IDENT K_LOGICAL IDENT
+           /* CREATE_REPLICATION_SLOT slot TEMPORARY LOGICAL plugin */
+           | K_CREATE_REPLICATION_SLOT IDENT opt_temporary K_LOGICAL IDENT
                {
                    CreateReplicationSlotCmd *cmd;
                    cmd = makeNode(CreateReplicationSlotCmd);
                    cmd->kind = REPLICATION_KIND_LOGICAL;
                    cmd->slotname = $2;
-                   cmd->plugin = $4;
+                   cmd->temporary = $3;
+                   cmd->plugin = $5;
                    $$ = (Node *) cmd;
                }
            ;
@@ -276,6 +279,11 @@ opt_reserve_wal:
            | /* EMPTY */                   { $$ = false; }
            ;
 
+opt_temporary:
+           K_TEMPORARY                     { $$ = true; }
+           | /* EMPTY */                   { $$ = false; }
+           ;
+
 opt_slot:
            K_SLOT IDENT
                { $$ = $2; }
index f83ec538b678dd9e6dfd2e76dd16165b3d0e777c..9f50ce64a54b3c52299bbf565b2e581a433e3c4e 100644 (file)
@@ -98,6 +98,7 @@ PHYSICAL          { return K_PHYSICAL; }
 RESERVE_WAL            { return K_RESERVE_WAL; }
 LOGICAL                { return K_LOGICAL; }
 SLOT               { return K_SLOT; }
+TEMPORARY          { return K_TEMPORARY; }
 
 ","                { return ','; }
 ";"                { return ';'; }
index 0b2575ee9d0b3b9f7b418202d2c7c0293bf1aba6..d8ed005e7ece28243a7db90889a4a21f60db568e 100644 (file)
@@ -47,6 +47,7 @@
 #include "storage/fd.h"
 #include "storage/proc.h"
 #include "storage/procarray.h"
+#include "utils/builtins.h"
 
 /*
  * Replication slot on-disk data structure.
@@ -98,7 +99,9 @@ int           max_replication_slots = 0;  /* the maximum number of replication
                                         * slots */
 
 static LWLockTranche ReplSlotIOLWLockTranche;
+
 static void ReplicationSlotDropAcquired(void);
+static void ReplicationSlotDropPtr(ReplicationSlot *slot);
 
 /* internal persistency functions */
 static void RestoreSlotFromDisk(const char *name);
@@ -329,7 +332,7 @@ ReplicationSlotAcquire(const char *name)
 {
    ReplicationSlot *slot = NULL;
    int         i;
-   int         active_pid = 0;
+   int         active_pid = 0; /* Keep compiler quiet */
 
    Assert(MyReplicationSlot == NULL);
 
@@ -346,7 +349,7 @@ ReplicationSlotAcquire(const char *name)
            SpinLockAcquire(&s->mutex);
            active_pid = s->active_pid;
            if (active_pid == 0)
-               s->active_pid = MyProcPid;
+               active_pid = s->active_pid = MyProcPid;
            SpinLockRelease(&s->mutex);
            slot = s;
            break;
@@ -359,7 +362,7 @@ ReplicationSlotAcquire(const char *name)
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("replication slot \"%s\" does not exist", name)));
-   if (active_pid != 0)
+   if (active_pid != MyProcPid)
        ereport(ERROR,
                (errcode(ERRCODE_OBJECT_IN_USE),
                 errmsg("replication slot \"%s\" is active for PID %d",
@@ -389,9 +392,12 @@ ReplicationSlotRelease(void)
         */
        ReplicationSlotDropAcquired();
    }
-   else
+   else if (slot->data.persistency == RS_PERSISTENT)
    {
-       /* Mark slot inactive.  We're not freeing it, just disconnecting. */
+       /*
+        * Mark persistent slot inactive.  We're not freeing it, just
+        * disconnecting.
+        */
        SpinLockAcquire(&slot->mutex);
        slot->active_pid = 0;
        SpinLockRelease(&slot->mutex);
@@ -405,6 +411,33 @@ ReplicationSlotRelease(void)
    LWLockRelease(ProcArrayLock);
 }
 
+/*
+ * Cleanup all temporary slots created in current session.
+ */
+void
+ReplicationSlotCleanup()
+{
+   int         i;
+
+   Assert(MyReplicationSlot == NULL);
+
+   /*
+    * No need for locking as we are only interested in slots active in
+    * current process and those are not touched by other processes.
+    */
+   for (i = 0; i < max_replication_slots; i++)
+   {
+       ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
+
+       if (s->active_pid == MyProcPid)
+       {
+           Assert(s->in_use && s->data.persistency == RS_TEMPORARY);
+
+           ReplicationSlotDropPtr(s);
+       }
+   }
+}
+
 /*
  * Permanently drop replication slot identified by the passed in name.
  */
@@ -419,14 +452,11 @@ ReplicationSlotDrop(const char *name)
 }
 
 /*
- * Permanently drop the currently acquired replication slot which will be
- * released by the point this function returns.
+ * Permanently drop the currently acquired replication slot.
  */
 static void
 ReplicationSlotDropAcquired(void)
 {
-   char        path[MAXPGPATH];
-   char        tmppath[MAXPGPATH];
    ReplicationSlot *slot = MyReplicationSlot;
 
    Assert(MyReplicationSlot != NULL);
@@ -434,6 +464,19 @@ ReplicationSlotDropAcquired(void)
    /* slot isn't acquired anymore */
    MyReplicationSlot = NULL;
 
+   ReplicationSlotDropPtr(slot);
+}
+
+/*
+ * Permanently drop the replication slot which will be released by the point
+ * this function returns.
+ */
+static void
+ReplicationSlotDropPtr(ReplicationSlot *slot)
+{
+   char        path[MAXPGPATH];
+   char        tmppath[MAXPGPATH];
+
    /*
     * If some other backend ran this code concurrently with us, we might try
     * to delete a slot with a certain name while someone else was trying to
@@ -448,9 +491,9 @@ ReplicationSlotDropAcquired(void)
    /*
     * Rename the slot directory on disk, so that we'll no longer recognize
     * this as a valid slot.  Note that if this fails, we've got to mark the
-    * slot inactive before bailing out.  If we're dropping an ephemeral slot,
-    * we better never fail hard as the caller won't expect the slot to
-    * survive and this might get called during error handling.
+    * slot inactive before bailing out.  If we're dropping an ephemeral or
+    * a temporary slot, we better never fail hard as the caller won't expect
+    * the slot to survive and this might get called during error handling.
     */
    if (rename(path, tmppath) == 0)
    {
@@ -469,7 +512,7 @@ ReplicationSlotDropAcquired(void)
    }
    else
    {
-       bool        fail_softly = slot->data.persistency == RS_EPHEMERAL;
+       bool        fail_softly = slot->data.persistency != RS_PERSISTENT;
 
        SpinLockAcquire(&slot->mutex);
        slot->active_pid = 0;
index f9087619d2b1a5bfd8f3f767d1351d12c2479d53..1f1c56cc21f7bbc09bbb8b9f42e471b28a0ed56c 100644 (file)
@@ -41,6 +41,7 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
 {
    Name        name = PG_GETARG_NAME(0);
    bool        immediately_reserve = PG_GETARG_BOOL(1);
+   bool        temporary = PG_GETARG_BOOL(2);
    Datum       values[2];
    bool        nulls[2];
    TupleDesc   tupdesc;
@@ -57,7 +58,8 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
    CheckSlotRequirements();
 
    /* acquire replication slot, this will check for conflicting names */
-   ReplicationSlotCreate(NameStr(*name), false, RS_PERSISTENT);
+   ReplicationSlotCreate(NameStr(*name), false,
+                         temporary ? RS_TEMPORARY : RS_PERSISTENT);
 
    values[0] = NameGetDatum(&MyReplicationSlot->data.name);
    nulls[0] = false;
@@ -96,6 +98,7 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
 {
    Name        name = PG_GETARG_NAME(0);
    Name        plugin = PG_GETARG_NAME(1);
+   bool        temporary = PG_GETARG_BOOL(2);
 
    LogicalDecodingContext *ctx = NULL;
 
@@ -116,11 +119,14 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
 
    /*
     * Acquire a logical decoding slot, this will check for conflicting names.
-    * Initially create it as ephemeral - that allows us to nicely handle
-    * errors during initialization because it'll get dropped if this
+    * Initially create persisent slot as ephemeral - that allows us to nicely
+    * handle errors during initialization because it'll get dropped if this
     * transaction fails. We'll make it persistent at the end.
+    * Temporary slots can be created as temporary from beginning as they get
+    * dropped on error as well.
     */
-   ReplicationSlotCreate(NameStr(*name), true, RS_EPHEMERAL);
+   ReplicationSlotCreate(NameStr(*name), true,
+                         temporary ? RS_TEMPORARY : RS_EPHEMERAL);
 
    /*
     * Create logical decoding context, to build the initial snapshot.
@@ -143,8 +149,9 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
    tuple = heap_form_tuple(tupdesc, values, nulls);
    result = HeapTupleGetDatum(tuple);
 
-   /* ok, slot is now fully created, mark it as persistent */
-   ReplicationSlotPersist();
+   /* ok, slot is now fully created, mark it as persistent if needed */
+   if (!temporary)
+       ReplicationSlotPersist();
    ReplicationSlotRelease();
 
    PG_RETURN_DATUM(result);
@@ -174,7 +181,7 @@ pg_drop_replication_slot(PG_FUNCTION_ARGS)
 Datum
 pg_get_replication_slots(PG_FUNCTION_ARGS)
 {
-#define PG_GET_REPLICATION_SLOTS_COLS 10
+#define PG_GET_REPLICATION_SLOTS_COLS 11
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
    TupleDesc   tupdesc;
    Tuplestorestate *tupstore;
@@ -219,6 +226,7 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
        Datum       values[PG_GET_REPLICATION_SLOTS_COLS];
        bool        nulls[PG_GET_REPLICATION_SLOTS_COLS];
 
+       ReplicationSlotPersistency  persistency;
        TransactionId xmin;
        TransactionId catalog_xmin;
        XLogRecPtr  restart_lsn;
@@ -246,6 +254,7 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
            namecpy(&plugin, &slot->data.plugin);
 
            active_pid = slot->active_pid;
+           persistency = slot->data.persistency;
        }
        SpinLockRelease(&slot->mutex);
 
@@ -269,6 +278,7 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
        else
            values[i++] = database;
 
+       values[i++] = BoolGetDatum(persistency == RS_TEMPORARY);
        values[i++] = BoolGetDatum(active_pid != 0);
 
        if (active_pid != 0)
index aa42d59610468ef128b3cf1fac7c5ddc97e15cec..b14d82153affb507cf74c087d3119a3bd2139ead 100644 (file)
@@ -266,6 +266,8 @@ WalSndErrorCleanup(void)
    if (MyReplicationSlot != NULL)
        ReplicationSlotRelease();
 
+   ReplicationSlotCleanup();
+
    replication_active = false;
    if (walsender_ready_to_stop)
        proc_exit(0);
@@ -796,18 +798,22 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
 
    if (cmd->kind == REPLICATION_KIND_PHYSICAL)
    {
-       ReplicationSlotCreate(cmd->slotname, false, RS_PERSISTENT);
+       ReplicationSlotCreate(cmd->slotname, false,
+                             cmd->temporary ? RS_TEMPORARY : RS_PERSISTENT);
    }
    else
    {
        CheckLogicalDecodingRequirements();
 
        /*
-        * Initially create the slot as ephemeral - that allows us to nicely
-        * handle errors during initialization because it'll get dropped if
-        * this transaction fails. We'll make it persistent at the end.
+        * Initially create persisent slot as ephemeral - that allows us to
+        * nicely handle errors during initialization because it'll get
+        * dropped if this transaction fails. We'll make it persistent at the
+        * end. Temporary slots can be created as temporary from beginning as
+        * they get dropped on error as well.
         */
-       ReplicationSlotCreate(cmd->slotname, true, RS_EPHEMERAL);
+       ReplicationSlotCreate(cmd->slotname, true,
+                             cmd->temporary ? RS_TEMPORARY : RS_EPHEMERAL);
    }
 
    initStringInfo(&output_message);
@@ -841,15 +847,18 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
        /* don't need the decoding context anymore */
        FreeDecodingContext(ctx);
 
-       ReplicationSlotPersist();
+       if (!cmd->temporary)
+           ReplicationSlotPersist();
    }
    else if (cmd->kind == REPLICATION_KIND_PHYSICAL && cmd->reserve_wal)
    {
        ReplicationSlotReserveWal();
 
-       /* Write this slot to disk */
        ReplicationSlotMarkDirty();
-       ReplicationSlotSave();
+
+       /* Write this slot to disk if it's permanent one. */
+       if (!cmd->temporary)
+           ReplicationSlotSave();
    }
 
    snprintf(xpos, sizeof(xpos), "%X/%X",
@@ -933,9 +942,6 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
 
    pq_endmessage(&buf);
 
-   /*
-    * release active status again, START_REPLICATION will reacquire it
-    */
    ReplicationSlotRelease();
 }
 
index 83e9ca15d186dc6e8ce3270e705ab668fd020617..276261bd7b379f6fbfac9c23d905d34aacb3842f 100644 (file)
@@ -810,6 +810,9 @@ ProcKill(int code, Datum arg)
    if (MyReplicationSlot != NULL)
        ReplicationSlotRelease();
 
+   /* Also cleanup all the temporary slots. */
+   ReplicationSlotCleanup();
+
    /*
     * Detach from any lock group of which we are a member.  If the leader
     * exist before all other group members, it's PGPROC will remain allocated
index cc847548a9fd4e609bbea296c7e91a8696ec4d28..b17923106a694b71881d3bc72dff0796bd08ac2d 100644 (file)
@@ -3878,6 +3878,9 @@ PostgresMain(int argc, char *argv[],
        if (MyReplicationSlot != NULL)
            ReplicationSlotRelease();
 
+       /* We also want to cleanup temporary slots on error. */
+       ReplicationSlotCleanup();
+
        /*
         * Now return to normal top-level context and clear ErrorContext for
         * next time.
index 96e77ec4379092431950f6b6d69e48e44da0a9b2..cd7b90981205b7d8ca6900c4e87226e90687da11 100644 (file)
@@ -5178,13 +5178,13 @@ DATA(insert OID = 5016 (  spg_box_quad_leaf_consistent  PGNSP PGUID 12 1 0 0 0 f
 DESCR("SP-GiST support for quad tree over box");
 
 /* replication slots */
-DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f t f v u 2 0 2249 "19 16" "{19,16,19,3220}" "{i,i,o,o}" "{slot_name,immediately_reserve,slot_name,xlog_position}" _null_ _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
+DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f t f v u 3 0 2249 "19 16 16" "{19,16,16,19,3220}" "{i,i,i,o,o}" "{slot_name,immediately_reserve,temporary,slot_name,xlog_position}" _null_ _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
 DESCR("create a physical replication slot");
 DATA(insert OID = 3780 (  pg_drop_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f t f v u 1 0 2278 "19" _null_ _null_ _null_ _null_ _null_ pg_drop_replication_slot _null_ _null_ _null_ ));
 DESCR("drop a replication slot");
-DATA(insert OID = 3781 (  pg_get_replication_slots PGNSP PGUID 12 1 10 0 0 f f f f f t s s 0 0 2249 "" "{19,19,25,26,16,23,28,28,3220,3220}" "{o,o,o,o,o,o,o,o,o,o}" "{slot_name,plugin,slot_type,datoid,active,active_pid,xmin,catalog_xmin,restart_lsn,confirmed_flush_lsn}" _null_ _null_ pg_get_replication_slots _null_ _null_ _null_ ));
+DATA(insert OID = 3781 (  pg_get_replication_slots PGNSP PGUID 12 1 10 0 0 f f f f f t s s 0 0 2249 "" "{19,19,25,26,16,16,23,28,28,3220,3220}" "{o,o,o,o,o,o,o,o,o,o,o}" "{slot_name,plugin,slot_type,datoid,temporary,active,active_pid,xmin,catalog_xmin,restart_lsn,confirmed_flush_lsn}" _null_ _null_ pg_get_replication_slots _null_ _null_ _null_ ));
 DESCR("information about replication slots currently in use");
-DATA(insert OID = 3786 (  pg_create_logical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f t f v u 2 0 2249 "19 19" "{19,19,25,3220}" "{i,i,o,o}" "{slot_name,plugin,slot_name,xlog_position}" _null_ _null_ pg_create_logical_replication_slot _null_ _null_ _null_ ));
+DATA(insert OID = 3786 (  pg_create_logical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f t f v u 3 0 2249 "19 19 16" "{19,19,16,25,3220}" "{i,i,i,o,o}" "{slot_name,plugin,temporary,slot_name,xlog_position}" _null_ _null_ pg_create_logical_replication_slot _null_ _null_ _null_ ));
 DESCR("set up a logical replication slot");
 DATA(insert OID = 3782 (  pg_logical_slot_get_changes PGNSP PGUID 12 1000 1000 25 0 f f f f f t v u 4 0 2249 "19 3220 23 1009" "{19,3220,23,1009,3220,28,25}" "{i,i,i,v,o,o,o}" "{slot_name,upto_lsn,upto_nchanges,options,location,xid,data}" _null_ _null_ pg_logical_slot_get_changes _null_ _null_ _null_ ));
 DESCR("get changes from replication slot");
index d2f1edbf0d1a9e72aabbc1112af775234079dd98..024b965a24b7b3ad12b4b2790a36d218a8a3be13 100644 (file)
@@ -55,6 +55,7 @@ typedef struct CreateReplicationSlotCmd
    char       *slotname;
    ReplicationKind kind;
    char       *plugin;
+   bool        temporary;
    bool        reserve_wal;
 } CreateReplicationSlotCmd;
 
index e00562d274fc882d28822ed4d1349f9f4d5c1bd0..b653e5c1962892364c2c24e9ad6214656fbc5d69 100644 (file)
@@ -28,7 +28,8 @@
 typedef enum ReplicationSlotPersistency
 {
    RS_PERSISTENT,
-   RS_EPHEMERAL
+   RS_EPHEMERAL,
+   RS_TEMPORARY
 } ReplicationSlotPersistency;
 
 /*
@@ -165,6 +166,7 @@ extern void ReplicationSlotDrop(const char *name);
 
 extern void ReplicationSlotAcquire(const char *name);
 extern void ReplicationSlotRelease(void);
+extern void ReplicationSlotCleanup(void);
 extern void ReplicationSlotSave(void);
 extern void ReplicationSlotMarkDirty(void);
 
index a8f35a76fabdb10424f262d917f3643e8063daa6..5314b9c207fdfd059c10f3fb18045c2939a82564 100644 (file)
@@ -1427,13 +1427,14 @@ pg_replication_slots| SELECT l.slot_name,
     l.slot_type,
     l.datoid,
     d.datname AS database,
+    l.temporary,
     l.active,
     l.active_pid,
     l.xmin,
     l.catalog_xmin,
     l.restart_lsn,
     l.confirmed_flush_lsn
-   FROM (pg_get_replication_slots() l(slot_name, plugin, slot_type, datoid, active, active_pid, xmin, catalog_xmin, restart_lsn, confirmed_flush_lsn)
+   FROM (pg_get_replication_slots() l(slot_name, plugin, slot_type, datoid, temporary, active, active_pid, xmin, catalog_xmin, restart_lsn, confirmed_flush_lsn)
      LEFT JOIN pg_database d ON ((l.datoid = d.oid)));
 pg_roles| SELECT pg_authid.rolname,
     pg_authid.rolsuper,