Re: [PATCHES] default resource limits

Tom Lane wrote:

>>Leaving aside the question of max_connections, which seems to be the
>>most controversial, is there any objection to the proposal to increase
>>the settings tried for shared_buffers (up to 4000) and max_fsm_pages (up
>>to 200000) ? If not, I'll apply a patch for those changes shortly.
>>
>>
>
>You probably need to fix the max-connections pass so that it applies the
>same changes to max_fsm_pages as the second pass does --- otherwise, its
>assumption that shared_buffers can really be set that way will be wrong.
>Other than that I didn't see any problem with the shared_buffers part of
>the patch.
>
>
>
>

revised patch attached, leaving max_connections alone except as above.

I'll apply this in a day or two, barring objection.

cheers

andrew
Index: src/bin/initdb/initdb.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/initdb/initdb.c,v
retrieving revision 1.101
diff -c -r1.101 initdb.c
*** src/bin/initdb/initdb.c    9 Dec 2005 15:51:14 -0000    1.101
--- src/bin/initdb/initdb.c    26 Dec 2005 22:44:09 -0000
***************
*** 120,125 ****
--- 120,126 ----
  /* defaults */
  static int    n_connections = 10;
  static int    n_buffers = 50;
+ static int  n_fsm_pages = 20000;

  /*
   * Warning messages for authentication methods
***************
*** 1084,1089 ****
--- 1085,1097 ----
  }

  /*
+  * max_fsm_pages setting used in both the shared_buffers and max_connections
+  * tests.
+  */
+
+ #define TEST_FSM(x) ( (x) > 1000 ? 50 * (x) : 20000 )
+
+ /*
   * check how many connections we can sustain
   */
  static void
***************
*** 1100,1111 ****

      for (i = 0; i < len; i++)
      {
          snprintf(cmd, sizeof(cmd),
                   "%s\"%s\" -boot -x0 %s "
                   "-c shared_buffers=%d -c max_connections=%d template1 "
                   "< \"%s\" > \"%s\" 2>&1%s",
                   SYSTEMQUOTE, backend_exec, boot_options,
!                  conns[i] * 5, conns[i],
                   DEVNULL, DEVNULL, SYSTEMQUOTE);
          status = system(cmd);
          if (status == 0)
--- 1108,1124 ----

      for (i = 0; i < len; i++)
      {
+         int test_buffs = conns[i] * 5;
+         int test_max_fsm =  TEST_FSM(test_buffs);
+
          snprintf(cmd, sizeof(cmd),
                   "%s\"%s\" -boot -x0 %s "
+                  "-c max_fsm_pages=%d "
                   "-c shared_buffers=%d -c max_connections=%d template1 "
                   "< \"%s\" > \"%s\" 2>&1%s",
                   SYSTEMQUOTE, backend_exec, boot_options,
!                  test_max_fsm,
!                  test_buffs, conns[i],
                   DEVNULL, DEVNULL, SYSTEMQUOTE);
          status = system(cmd);
          if (status == 0)
***************
*** 1125,1146 ****
  test_buffers(void)
  {
      char        cmd[MAXPGPATH];
!     static const int bufs[] = {1000, 900, 800, 700, 600, 500,
!     400, 300, 200, 100, 50};
      static const int len = sizeof(bufs) / sizeof(int);
      int            i,
!                 status;

!     printf(_("selecting default shared_buffers ... "));
      fflush(stdout);

      for (i = 0; i < len; i++)
      {
          snprintf(cmd, sizeof(cmd),
                   "%s\"%s\" -boot -x0 %s "
                   "-c shared_buffers=%d -c max_connections=%d template1 "
                   "< \"%s\" > \"%s\" 2>&1%s",
                   SYSTEMQUOTE, backend_exec, boot_options,
                   bufs[i], n_connections,
                   DEVNULL, DEVNULL, SYSTEMQUOTE);
          status = system(cmd);
--- 1138,1167 ----
  test_buffers(void)
  {
      char        cmd[MAXPGPATH];
!     static const int bufs[] = {
!       4000, 3500, 3000, 2500, 2000, 1500,
!       1000, 900, 800, 700, 600, 500,
!       400, 300, 200, 100, 50
!     };
      static const int len = sizeof(bufs) / sizeof(int);
      int            i,
!                 status,
!                 test_max_fsm_pages;

!     printf(_("selecting default shared_buffers/max_fsm_pages ... "));
      fflush(stdout);

      for (i = 0; i < len; i++)
      {
+         test_max_fsm_pages = TEST_FSM(bufs[i]);
+
          snprintf(cmd, sizeof(cmd),
                   "%s\"%s\" -boot -x0 %s "
+                  "-c max_fsm_pages=%d "
                   "-c shared_buffers=%d -c max_connections=%d template1 "
                   "< \"%s\" > \"%s\" 2>&1%s",
                   SYSTEMQUOTE, backend_exec, boot_options,
+                  test_max_fsm_pages,
                   bufs[i], n_connections,
                   DEVNULL, DEVNULL, SYSTEMQUOTE);
          status = system(cmd);
***************
*** 1150,1157 ****
      if (i >= len)
          i = len - 1;
      n_buffers = bufs[i];

!     printf("%d\n", n_buffers);
  }

  /*
--- 1171,1179 ----
      if (i >= len)
          i = len - 1;
      n_buffers = bufs[i];
+     n_fsm_pages = test_max_fsm_pages;

!     printf("%d/%d\n", n_buffers, n_fsm_pages);
  }

  /*
***************
*** 1177,1182 ****
--- 1199,1207 ----
      snprintf(repltok, sizeof(repltok), "shared_buffers = %d", n_buffers);
      conflines = replace_token(conflines, "#shared_buffers = 1000", repltok);

+     snprintf(repltok, sizeof(repltok), "max_fsm_pages = %d", n_fsm_pages);
+     conflines = replace_token(conflines, "#max_fsm_pages = 20000", repltok);
+
  #if DEF_PGPORT != 5432
      snprintf(repltok, sizeof(repltok), "#port = %d", DEF_PGPORT);
      conflines = replace_token(conflines, "#port = 5432", repltok);