Bruce Momjian wrote:
> Yes, that was my calculus too. I realized that we create session ids by
> merging the process id and backend start time, so I went ahead and added
> the postmaster start time epoch to the postmaster.pid file. While there
> is no way to pass back the postmaster start time from PQping, I added
> code to pg_ctl to make sure the time in the postmaster.pid file is not
> _before_ pg_ctl started running. We only check PQping() after we have
> started the postmaster ourselves, so it fits our needs.
Tom suggested that there might be clock skew between pg_ctl and the
postmaster, so I added a 2-second slop in checking the postmaster start
time. Tom also wanted the connection information to be output all at
once, but that causes a problem with detecting pre-9.1 servers so I
avoided it.
Updated patch attached.
--
Bruce Momjian <br...@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index cda7f64..86bc5a6 100644
*** /tmp/pgdiff.14558/cXBdee_storage.sgml Wed Dec 29 13:42:38 2010
--- doc/src/sgml/storage.sgml Wed Dec 29 12:11:03 2010
*************** last started with</entry>
*** 117,124 ****
<row>
<entry><filename>postmaster.pid</></entry>
<entry>A lock file recording the current postmaster process id (PID),
! cluster data directory, port number, Unix domain socket directory,
! and shared memory segment ID</entry>
</row>
</tbody>
--- 117,125 ----
<row>
<entry><filename>postmaster.pid</></entry>
<entry>A lock file recording the current postmaster process id (PID),
! postmaster start time, cluster data directory, port number, user-specified
! Unix domain socket directory, first valid listen_address host, and
! shared memory segment ID</entry>
</row>
</tbody>
diff --git a/src/backend/port/ipc_test.c b/src/backend/port/ipc_test.c
index a003dc9..461a7a6 100644
*** /tmp/pgdiff.14558/o3NlPc_ipc_test.c Wed Dec 29 13:42:38 2010
--- src/backend/port/ipc_test.c Wed Dec 29 12:11:03 2010
*************** on_exit_reset(void)
*** 104,110 ****
}
void
! RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
{
}
--- 104,110 ----
}
void
! AddToLockFile(int target_line, const char *str)
{
}
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c
index d970eb2..ff77099 100644
*** /tmp/pgdiff.14558/mac69b_sysv_shmem.c Wed Dec 29 13:42:38 2010
--- src/backend/port/sysv_shmem.c Wed Dec 29 12:11:03 2010
*************** InternalIpcMemoryCreate(IpcMemoryKey mem
*** 198,206 ****
/* Register on-exit routine to detach new segment before deleting */
on_shmem_exit(IpcMemoryDetach, PointerGetDatum(memAddress));
! /* Record key and ID in lockfile for data directory. */
! RecordSharedMemoryInLockFile((unsigned long) memKey,
! (unsigned long) shmid);
return memAddress;
}
--- 198,214 ----
/* Register on-exit routine to detach new segment before deleting */
on_shmem_exit(IpcMemoryDetach, PointerGetDatum(memAddress));
! /*
! * Append record key and ID in lockfile for data directory. Format
! * to try to keep it the same length.
! */
! {
! char line[32];
!
! sprintf(line, "%9lu %9lu\n", (unsigned long) memKey,
! (unsigned long) shmid);
! AddToLockFile(LOCK_FILE_LINES, line);
! }
return memAddress;
}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index a46a323..c1e553a 100644
*** /tmp/pgdiff.14558/GKd28a_postmaster.c Wed Dec 29 13:42:38 2010
--- src/backend/postmaster/postmaster.c Wed Dec 29 12:11:03 2010
*************** PostmasterMain(int argc, char *argv[])
*** 483,489 ****
int status;
char *userDoption = NULL;
int i;
!
MyProcPid = PostmasterPid = getpid();
MyStartTime = time(NULL);
--- 483,490 ----
int status;
char *userDoption = NULL;
int i;
! bool connection_line_output = false;
!
MyProcPid = PostmasterPid = getpid();
MyStartTime = time(NULL);
*************** PostmasterMain(int argc, char *argv[])
*** 860,869 ****
--- 861,882 ----
UnixSocketDir,
ListenSocket, MAXLISTEN);
else
+ {
status = StreamServerPort(AF_UNSPEC, curhost,
(unsigned short) PostPortNumber,
UnixSocketDir,
ListenSocket, MAXLISTEN);
+ /* must supply a valid listen_address for PQping() */
+ if (!connection_line_output)
+ {
+ char line[MAXPGPATH + 2];
+
+ sprintf(line, "%s\n", curhost);
+ AddToLockFile(LOCK_FILE_LINES - 1, line);
+ connection_line_output = true;
+ }
+ }
+
if (status == STATUS_OK)
success++;
else
*************** PostmasterMain(int argc, char *argv[])
*** 880,885 ****
--- 893,902 ----
pfree(rawstring);
}
+ /* Supply an empty listen_address line for PQping() */
+ if (!connection_line_output)
+ AddToLockFile(LOCK_FILE_LINES - 1, "\n");
+
#ifdef USE_BONJOUR
/* Register for Bonjour only if we opened TCP socket(s) */
if (enable_bonjour && ListenSocket[0] != PGINVALID_SOCKET)
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index d74b5cc..6935786 100644
*** /tmp/pgdiff.14558/IzFLnd_miscinit.c Wed Dec 29 13:42:38 2010
--- src/backend/utils/init/miscinit.c Wed Dec 29 12:11:03 2010
***************
*** 46,52 ****
#define DIRECTORY_LOCK_FILE "postmaster.pid"
!
ProcessingMode Mode = InitProcessing;
/* Note: we rely on this to initialize as zeroes */
--- 46,65 ----
#define DIRECTORY_LOCK_FILE "postmaster.pid"
! /*
! * The lock file contents are:
! *
! * line #
! * 1 pid
! * 2 postmaster start time
! * 3 data directory
! * 4 port #
! * 5 user-specified socket directory
! * (the lines below are added later)
! * 6 first valid listen_address
! * 7 shared memory key
! */
!
ProcessingMode Mode = InitProcessing;
/* Note: we rely on this to initialize as zeroes */
*************** CreateLockFile(const char *filename, boo
*** 659,665 ****
bool isDDLock, const char *refName)
{
int fd;
! char buffer[MAXPGPATH * 2 + 256];
int ntries;
int len;
int encoded_pid;
--- 672,678 ----
bool isDDLock, const char *refName)
{
int fd;
! char buffer[MAXPGPATH * 3 + 256];
int ntries;
int len;
int encoded_pid;
*************** CreateLockFile(const char *filename, boo
*** 826,836 ****
if (isDDLock)
{
char *ptr = buffer;
! unsigned long id1,
! id2;
int lineno;
! for (lineno = 1; lineno <= 4; lineno++)
{
if ((ptr = strchr(ptr, '\n')) == NULL)
{
--- 839,848 ----
if (isDDLock)
{
char *ptr = buffer;
! unsigned long id1, id2;
int lineno;
! for (lineno = 1; lineno <= LOCK_FILE_LINES - 1; lineno++)
{
if ((ptr = strchr(ptr, '\n')) == NULL)
{
*************** CreateLockFile(const char *filename, boo
*** 874,882 ****
/*
* Successfully created the file, now fill it.
*/
! snprintf(buffer, sizeof(buffer), "%d\n%s\n%d\n%s\n",
amPostmaster ? (int) my_pid : -((int) my_pid),
! DataDir, PostPortNumber, UnixSocketDir);
errno = 0;
if (write(fd, buffer, strlen(buffer)) != strlen(buffer))
{
--- 886,895 ----
/*
* Successfully created the file, now fill it.
*/
! snprintf(buffer, sizeof(buffer), "%d\n%ld\n%s\n%d\n%s\n",
amPostmaster ? (int) my_pid : -((int) my_pid),
! (long) MyStartTime, DataDir, PostPortNumber,
! UnixSocketDir);
errno = 0;
if (write(fd, buffer, strlen(buffer)) != strlen(buffer))
{
*************** TouchSocketLockFile(void)
*** 985,1008 ****
}
}
/*
! * Append information about a shared memory segment to the data directory
! * lock file.
! *
! * This may be called multiple times in the life of a postmaster, if we
! * delete and recreate shmem due to backend crash. Therefore, be prepared
! * to overwrite existing information. (As of 7.1, a postmaster only creates
! * one shm seg at a time; but for the purposes here, if we did have more than
! * one then any one of them would do anyway.)
*/
void
! RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
{
int fd;
int len;
int lineno;
char *ptr;
! char buffer[MAXPGPATH * 2 + 256];
fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
if (fd < 0)
--- 998,1016 ----
}
}
+
/*
! * Add lines to the data directory lock file. This erases all following
! * lines, but that is OK because lines are added in order.
*/
void
! AddToLockFile(int target_line, const char *str)
{
int fd;
int len;
int lineno;
char *ptr;
! char buffer[MAXPGPATH * 3 + 256];
fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
if (fd < 0)
*************** RecordSharedMemoryInLockFile(unsigned lo
*** 1029,1035 ****
* Skip over first four lines (PID, pgdata, portnum, socketdir).
*/
ptr = buffer;
! for (lineno = 1; lineno <= 4; lineno++)
{
if ((ptr = strchr(ptr, '\n')) == NULL)
{
--- 1037,1043 ----
* Skip over first four lines (PID, pgdata, portnum, socketdir).
*/
ptr = buffer;
! for (lineno = 1; lineno < target_line; lineno++)
{
if ((ptr = strchr(ptr, '\n')) == NULL)
{
*************** RecordSharedMemoryInLockFile(unsigned lo
*** 1040,1050 ****
ptr++;
}
! /*
! * Append key information. Format to try to keep it the same length
! * always (trailing junk won't hurt, but might confuse humans).
! */
! sprintf(ptr, "%9lu %9lu\n", id1, id2);
/*
* And rewrite the data. Since we write in a single kernel call, this
--- 1048,1054 ----
ptr++;
}
! strlcat(buffer, str, sizeof(buffer));
/*
* And rewrite the data. Since we write in a single kernel call, this
diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index 5e1b772..92ea514 100644
*** /tmp/pgdiff.14558/gFBQjc_pg_ctl.c Wed Dec 29 13:42:38 2010
--- src/bin/pg_ctl/pg_ctl.c Wed Dec 29 12:32:48 2010
***************
*** 22,27 ****
--- 22,28 ----
#include <locale.h>
#include <signal.h>
+ #include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
*************** static void read_post_opts(void);
*** 138,143 ****
--- 139,145 ----
static PGPing test_postmaster_connection(bool);
static bool postmaster_is_alive(pid_t pid);
+ static time_t start_time;
static char postopts_file[MAXPGPATH];
static char pid_file[MAXPGPATH];
*************** static PGPing
*** 404,416 ****
test_postmaster_connection(bool do_checkpoint)
{
int portnum = 0;
! char socket_dir[MAXPGPATH];
char connstr[MAXPGPATH + 256];
PGPing ret = PQPING_OK; /* assume success for wait == zero */
char **optlines;
int i;
! socket_dir[0] = '\0';
connstr[0] = '\0';
for (i = 0; i < wait_seconds; i++)
--- 406,418 ----
test_postmaster_connection(bool do_checkpoint)
{
int portnum = 0;
! char host_str[MAXPGPATH];
char connstr[MAXPGPATH + 256];
PGPing ret = PQPING_OK; /* assume success for wait == zero */
char **optlines;
int i;
! host_str[0] = '\0';
connstr[0] = '\0';
for (i = 0; i < wait_seconds; i++)
*************** test_postmaster_connection(bool do_check
*** 425,437 ****
* 0 lock file created but status not written
* 2 pre-9.1 server, shared memory not created
* 3 pre-9.1 server, shared memory created
! * 4 9.1+ server, shared memory not created
! * 5 9.1+ server, shared memory created
*
* For pre-9.1 Unix servers, we grab the port number from the
* shmem key (first value on line 3). Pre-9.1 Win32 has no
! * written shmem key, so we fail. 9.1+ writes both the port
! * number and socket address in the file for us to use.
* (PG_VERSION could also have told us the major version.)
*/
--- 427,440 ----
* 0 lock file created but status not written
* 2 pre-9.1 server, shared memory not created
* 3 pre-9.1 server, shared memory created
! * 5 9.1+ server, listen host not created
! * 6 9.1+ server, shared memory not created
! * 7 9.1+ server, shared memory created
*
* For pre-9.1 Unix servers, we grab the port number from the
* shmem key (first value on line 3). Pre-9.1 Win32 has no
! * written shmem key, so we fail. 9.1+ writes connection
! * information in the file for us to use.
* (PG_VERSION could also have told us the major version.)
*/
*************** test_postmaster_connection(bool do_check
*** 439,445 ****
if ((optlines = readfile(pid_file)) != NULL &&
optlines[0] != NULL &&
optlines[1] != NULL &&
! optlines[2] != NULL)
{
/* A 3-line file? */
if (optlines[3] == NULL)
--- 442,451 ----
if ((optlines = readfile(pid_file)) != NULL &&
optlines[0] != NULL &&
optlines[1] != NULL &&
! optlines[2] != NULL &&
! /* pre-9.1 server or listen_address line is present? */
! (optlines[3] == NULL ||
! optlines[5] != NULL))
{
/* A 3-line file? */
if (optlines[3] == NULL)
*************** test_postmaster_connection(bool do_check
*** 459,489 ****
return PQPING_NO_ATTEMPT;
}
}
! else /* 9.1+ server */
{
! portnum = atoi(optlines[2]);
!
! /* Get socket directory, if specified. */
! if (optlines[3][0] != '\n')
{
! /*
! * While unix_socket_directory can accept relative
! * directories, libpq's host must have a leading slash
! * to indicate a socket directory.
! */
! if (optlines[3][0] != '/')
! {
! write_stderr(_("%s: -w option cannot use a relative socket directory specification\n"),
! progname);
! return PQPING_NO_ATTEMPT;
! }
! strlcpy(socket_dir, optlines[3], MAXPGPATH);
! /* remove newline */
! if (strchr(socket_dir, '\n') != NULL)
! *strchr(socket_dir, '\n') = '\0';
}
! }
/*
* We need to set connect_timeout otherwise on Windows the
* Service Control Manager (SCM) will probably timeout first.
--- 465,517 ----
return PQPING_NO_ATTEMPT;
}
}
! else
{
! /*
! * Easy check to see if we are looking at the right
! * data directory: Is the postmaster older than this
! * execution of pg_ctl? Subtract 2 seconds to account
! * for possible clock skew between pg_ctl and the
! * postmaster.
! */
! if (atol(optlines[1]) < start_time - 2)
{
! write_stderr(_("%s: this data directory is running an older postmaster\n"),
! progname);
! return PQPING_NO_ATTEMPT;
}
!
! portnum = atoi(optlines[3]);
+ /*
+ * Determine the proper host string to use.
+ */
+ #ifdef HAVE_UNIX_SOCKETS
+ /*
+ * Use socket directory, if specified. We assume if we
+ * have unix sockets, the server does too because we
+ * just started the postmaster.
+ */
+ /*
+ * While unix_socket_directory can accept relative
+ * directories, libpq's host must have a leading slash
+ * to indicate a socket directory.
+ */
+ if (optlines[4][0] != '\n' && optlines[4][0] != '/')
+ {
+ write_stderr(_("%s: -w option cannot use a relative socket directory specification\n"),
+ progname);
+ return PQPING_NO_ATTEMPT;
+ }
+ strlcpy(host_str, optlines[4], sizeof(host_str));
+ #else
+ strlcpy(host_str, optlines[5], sizeof(host_str));
+ #endif
+ /* remove newline */
+ if (strchr(host_str, '\n') != NULL)
+ *strchr(host_str, '\n') = '\0';
+ }
+
/*
* We need to set connect_timeout otherwise on Windows the
* Service Control Manager (SCM) will probably timeout first.
*************** test_postmaster_connection(bool do_check
*** 491,499 ****
snprintf(connstr, sizeof(connstr),
"dbname=postgres port=%d connect_timeout=5", portnum);
! if (socket_dir[0] != '\0')
snprintf(connstr + strlen(connstr), sizeof(connstr) - strlen(connstr),
! " host='%s'", socket_dir);
}
}
--- 519,527 ----
snprintf(connstr, sizeof(connstr),
"dbname=postgres port=%d connect_timeout=5", portnum);
! if (host_str[0] != '\0')
snprintf(connstr + strlen(connstr), sizeof(connstr) - strlen(connstr),
! " host='%s'", host_str);
}
}
*************** main(int argc, char **argv)
*** 1756,1761 ****
--- 1784,1790 ----
progname = get_progname(argv[0]);
set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_ctl"));
+ start_time = time(NULL);
/*
* save argv[0] so do_start() can look for the postmaster if necessary. we
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 032875e..72e1dc8 100644
*** /tmp/pgdiff.14558/onEvLd_miscadmin.h Wed Dec 29 13:42:38 2010
--- src/include/miscadmin.h Wed Dec 29 12:11:03 2010
*************** extern PGDLLIMPORT bool process_shared_p
*** 348,358 ****
extern char *shared_preload_libraries_string;
extern char *local_preload_libraries_string;
extern void CreateDataDirLockFile(bool amPostmaster);
extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
extern void TouchSocketLockFile(void);
! extern void RecordSharedMemoryInLockFile(unsigned long id1,
! unsigned long id2);
extern void ValidatePgVersion(const char *path);
extern void process_shared_preload_libraries(void);
extern void process_local_preload_libraries(void);
--- 348,358 ----
extern char *shared_preload_libraries_string;
extern char *local_preload_libraries_string;
+ #define LOCK_FILE_LINES 7
extern void CreateDataDirLockFile(bool amPostmaster);
extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
extern void TouchSocketLockFile(void);
! extern void AddToLockFile(int target_line, const char *str);
extern void ValidatePgVersion(const char *path);
extern void process_shared_preload_libraries(void);
extern void process_local_preload_libraries(void);
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