<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.192 2003/07/09 08:52:56 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.193 2003/07/14 20:00:22 tgl Exp $
-->
<Chapter Id="runtime">
<listitem>
<para>
Determines the maximum number of concurrent connections to the
- database server. The default is 32 (unless altered while
- building the server). This parameter can only be set at server
- start.
+ database server. The default is typically 100, but may be less
+ if your kernel settings will not support it (as determined
+ during <application>initdb</>).
+ This parameter can only be set at server start.
+ </para>
+
+ <para>
+ Increasing this parameter may cause <productname>PostgreSQL</>
+ to request more <systemitem class="osname">System V</> shared
+ memory or semaphores than your operating system's default configuration
+ allows. See <xref linkend="sysvipc"> for information on how to
+ adjust these parameters, if necessary.
</para>
</listitem>
</varlistentry>
<listitem>
<para>
Sets the number of shared memory buffers used by the database
- server. The default is 64. Each buffer is typically 8192
- bytes. This must be greater than 16, as well as at least twice
- the value of <varname>MAX_CONNECTIONS</varname>; however, a
- higher value can often improve performance.
- Values of a few thousand are recommended
- for production installations. This option can only be set at
- server start.
+ server. The default is typically 1000, but may be less
+ if your kernel settings will not support it (as determined
+ during <application>initdb</>). Each buffer is 8192
+ bytes, unless a different value of <literal>BLCKSZ</> was chosen
+ when building the server. This setting must be at least 16,
+ as well as at least twice the value of
+ <varname>MAX_CONNECTIONS</varname>; however, settings significantly
+ higher than the minimum are usually needed for good performance.
+ Values of a few thousand are recommended for production installations.
+ This option can only be set at server start.
</para>
<para>
number</quote>, to detect collision with semaphore sets used by
other applications. The maximum number of semaphores in the system
is set by <varname>SEMMNS</>, which consequently must be at least
- as high as the connection setting plus one extra for each 16
+ as high as <literal>max_connections</> plus one extra for each 16
allowed connections (see the formula in <xref
linkend="sysvipc-parameters">). The parameter <varname>SEMMNI</>
determines the limit on the number of semaphore sets that can
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/port/sysv_shmem.c,v 1.10 2003/05/08 19:17:07 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/port/sysv_shmem.c,v 1.11 2003/07/14 20:00:22 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static void *InternalIpcMemoryCreate(IpcMemoryKey memKey, uint32 size);
static void IpcMemoryDetach(int status, Datum shmaddr);
static void IpcMemoryDelete(int status, Datum shmId);
-static void *PrivateMemoryCreate(uint32 size);
-static void PrivateMemoryDelete(int status, Datum memaddr);
static PGShmemHeader *PGSharedMemoryAttach(IpcMemoryKey key,
- IpcMemoryId *shmid, void *addr);
+ IpcMemoryId *shmid);
/*
}
-/* ----------------------------------------------------------------
- * private memory support
- *
- * Rather than allocating shmem segments with IPC_PRIVATE key, we
- * just malloc() the requested amount of space. This code emulates
- * the needed shmem functions.
- * ----------------------------------------------------------------
- */
-
-static void *
-PrivateMemoryCreate(uint32 size)
-{
- void *memAddress;
-
- memAddress = malloc(size);
- if (!memAddress)
- {
- fprintf(stderr, "PrivateMemoryCreate: malloc(%u) failed\n", size);
- proc_exit(1);
- }
- MemSet(memAddress, 0, size); /* keep Purify quiet */
-
- /* Register on-exit routine to release storage */
- on_shmem_exit(PrivateMemoryDelete, PointerGetDatum(memAddress));
-
- return memAddress;
-}
-
-static void
-PrivateMemoryDelete(int status, Datum memaddr)
-{
- free(DatumGetPointer(memaddr));
-}
-
-
/*
* PGSharedMemoryCreate
*
* collision with non-Postgres shmem segments. The idea here is to detect and
* re-use keys that may have been assigned by a crashed postmaster or backend.
*
+ * makePrivate means to always create a new segment, rather than attach to
+ * or recycle any existing segment.
+ *
* The port number is passed for possible use as a key (for SysV, we use
* it to generate the starting shmem key). In a standalone backend,
* zero will be passed.
/* Just attach and return the pointer */
if (ExecBackend && UsedShmemSegAddr != NULL && !makePrivate)
{
- if ((hdr = (PGShmemHeader *) memAddress = PGSharedMemoryAttach(
- UsedShmemSegID, &shmid, UsedShmemSegAddr)) == NULL)
+ if ((hdr = PGSharedMemoryAttach(UsedShmemSegID, &shmid)) == NULL)
{
fprintf(stderr, "Unable to attach to proper memory at fixed address: shmget(key=%d, addr=%p) failed: %s\n",
(int) UsedShmemSegID, UsedShmemSegAddr, strerror(errno));
return hdr;
}
- /* Create shared memory */
-
- NextShmemSegID = port * 1000 + 1;
+ /* Loop till we find a free IPC key */
+ NextShmemSegID = port * 1000;
- for (;;NextShmemSegID++)
+ for (NextShmemSegID++;; NextShmemSegID++)
{
- /* Special case if creating a private segment --- just malloc() it */
- if (makePrivate)
- {
- memAddress = PrivateMemoryCreate(size);
- break;
- }
-
/* Try to create new segment */
memAddress = InternalIpcMemoryCreate(NextShmemSegID, size);
if (memAddress)
break; /* successful create and attach */
/* Check shared memory and possibly remove and recreate */
-
- if ((hdr = (PGShmemHeader *) memAddress = PGSharedMemoryAttach(
- NextShmemSegID, &shmid, UsedShmemSegAddr)) == NULL)
+
+ if (makePrivate) /* a standalone backend shouldn't do this */
+ continue;
+
+ if ((memAddress = PGSharedMemoryAttach(NextShmemSegID, &shmid)) == NULL)
continue; /* can't attach, not one of mine */
/*
* If I am not the creator and it belongs to an extant process,
* continue.
*/
+ hdr = (PGShmemHeader *) memAddress;
if (hdr->creatorPID != getpid())
{
if (kill(hdr->creatorPID, 0) == 0 || errno != ESRCH)
/*
- * Attach to shared memory and make sure it has a Postgres header
+ * Attach to shared memory and make sure it has a Postgres header
+ *
+ * Returns attach address if OK, else NULL
*/
static PGShmemHeader *
-PGSharedMemoryAttach(IpcMemoryKey key, IpcMemoryId *shmid, void *addr)
+PGSharedMemoryAttach(IpcMemoryKey key, IpcMemoryId *shmid)
{
PGShmemHeader *hdr;
if ((*shmid = shmget(key, sizeof(PGShmemHeader), 0)) < 0)
return NULL;
- hdr = (PGShmemHeader *) shmat(*shmid, UsedShmemSegAddr,
+ hdr = (PGShmemHeader *) shmat(*shmid,
+ UsedShmemSegAddr,
#if defined(solaris) && defined(__sparc__)
- /* use intimate shared memory on SPARC Solaris */
- SHM_SHARE_MMU
+ /* use intimate shared memory on Solaris */
+ SHM_SHARE_MMU
#else
- 0
+ 0
#endif
);
shmdt(hdr);
return NULL; /* segment belongs to a non-Postgres app */
}
+
return hdr;
}
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.122 2003/06/27 14:45:30 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.123 2003/07/14 20:00:22 tgl Exp $
*
*
*-------------------------------------------------------------------------
{
/*
* We're running a postgres bootstrap process or a standalone backend.
- * Create private "shmem" and semaphores. Force MaxBackends to 1 so
- * that we don't allocate more resources than necessary.
+ * Create private "shmem" and semaphores.
*/
- SetConfigOption("max_connections", "1",
- PGC_POSTMASTER, PGC_S_OVERRIDE);
-
CreateSharedMemoryAndSemaphores(true, MaxBackends, 0);
}
}
#client_encoding = sql_ascii # actually, defaults to database encoding
# These settings are initialized by initdb -- they may be changed
+#lc_messages = 'C' # locale for system error message strings
+#lc_monetary = 'C' # locale for monetary formatting
+#lc_numeric = 'C' # locale for number formatting
+#lc_time = 'C' # locale for time formatting
# Other Defaults
# Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
# Portions Copyright (c) 1994, Regents of the University of California
#
-# $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.193 2003/07/04 16:41:21 tgl Exp $
+# $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.194 2003/07/14 20:00:23 tgl Exp $
#
#-------------------------------------------------------------------------
##########################################################################
#
+# DETERMINE PLATFORM-SPECIFIC CONFIG SETTINGS
+#
+# Use reasonable values if kernel will let us, else scale back
+
+cp /dev/null "$PGDATA"/postgresql.conf || exit_nicely
+
+$ECHO_N "selecting default shared_buffers... "$ECHO_C
+
+for nbuffers in 1000 900 800 700 600 500 400 300 200 100 50
+do
+ TEST_OPT="$PGSQL_OPT -c shared_buffers=$nbuffers -c max_connections=5"
+ if "$PGPATH"/postgres $TEST_OPT template1 </dev/null >/dev/null 2>&1
+ then
+ break
+ fi
+done
+
+echo "$nbuffers"
+
+$ECHO_N "selecting default max_connections... "$ECHO_C
+
+for nconns in 100 50 40 30 20 10
+do
+ TEST_OPT="$PGSQL_OPT -c shared_buffers=$nbuffers -c max_connections=$nconns"
+ if "$PGPATH"/postgres $TEST_OPT template1 </dev/null >/dev/null 2>&1
+ then
+ break
+ fi
+done
+
+echo "$nconns"
+
+##########################################################################
+#
# CREATE CONFIG FILES
$ECHO_N "creating configuration files... "$ECHO_C
cp "$PG_HBA_SAMPLE" "$PGDATA"/pg_hba.conf || exit_nicely
cp "$PG_IDENT_SAMPLE" "$PGDATA"/pg_ident.conf || exit_nicely
-(
- trigger="# These settings are initialized by initdb -- they may be changed"
- sed -n "1,/$trigger/p" "$POSTGRESQL_CONF_SAMPLE"
- for cat in MESSAGES MONETARY NUMERIC TIME; do
- echo "LC_$cat = '`pg_getlocale $cat`'"
- done
- sed -n "1,/$trigger/!p" "$POSTGRESQL_CONF_SAMPLE"
-) > "$PGDATA"/postgresql.conf || exit_nicely
+sed -e "s/^#shared_buffers = 64/shared_buffers = $nbuffers/" \
+ -e "s/^#max_connections = 32/max_connections = $nconns/" \
+ -e "s/^#lc_messages = 'C'/lc_messages = '`pg_getlocale MESSAGES`'/" \
+ -e "s/^#lc_monetary = 'C'/lc_monetary = '`pg_getlocale MONETARY`'/" \
+ -e "s/^#lc_numeric = 'C'/lc_numeric = '`pg_getlocale NUMERIC`'/" \
+ -e "s/^#lc_time = 'C'/lc_time = '`pg_getlocale TIME`'/" \
+ "$POSTGRESQL_CONF_SAMPLE" > "$PGDATA"/postgresql.conf || exit_nicely
chmod 0600 "$PGDATA"/pg_hba.conf "$PGDATA"/pg_ident.conf \
"$PGDATA"/postgresql.conf
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