src/janitor.c

   1 /*
   2  * PgBouncer - Lightweight connection pooler for PostgreSQL.
   3  *
   4  * Copyright (c) 2007-2009  Marko Kreen, Skype Technologies OÜ
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /*
  20  * Periodic maintenance.
  21  */
  22
  23 #include "bouncer.h"
  24
  25 /* do full maintenance 3x per second */
  26 static struct timeval full_maint_period = {0, USEC / 3};
  27 static struct event full_maint_ev;
  28
  29 /* close all sockets in server list */
  30 static void close_server_list(StatList *sk_list, const char *reason)
  31 {
  32         List *item, *tmp;
  33         PgSocket *server;
  34
  35         statlist_for_each_safe(item, sk_list, tmp) {
  36                 server = container_of(item, PgSocket, head);
  37                 disconnect_server(server, true, "%s", reason);
  38         }
  39 }
  40
  41 static void close_client_list(StatList *sk_list, const char *reason)
  42 {
  43         List *item, *tmp;
  44         PgSocket *client;
  45
  46         statlist_for_each_safe(item, sk_list, tmp) {
  47                 client = container_of(item, PgSocket, head);
  48                 disconnect_client(client, true, "%s", reason);
  49         }
  50 }
  51
  52 bool suspend_socket(PgSocket *sk, bool force_suspend)
  53 {
  54         if (sk->suspended)
  55                 return true;
  56
  57         if (sbuf_is_empty(&sk->sbuf)) {
  58                 if (sbuf_pause(&sk->sbuf))
  59                         sk->suspended = 1;
  60         }
  61
  62         if (sk->suspended || !force_suspend)
  63                 return sk->suspended;
  64
  65         if (is_server_socket(sk))
  66                 disconnect_server(sk, true, "suspend_timeout");
  67         else
  68                 disconnect_client(sk, true, "suspend_timeout");
  69         return true;
  70 }
  71
  72 /* suspend all sockets in socket list */
  73 static int suspend_socket_list(StatList *list, bool force_suspend)
  74 {
  75         List *item, *tmp;
  76         PgSocket *sk;
  77         int active = 0;
  78
  79         statlist_for_each_safe(item, list, tmp) {
  80                 sk = container_of(item, PgSocket, head);
  81                 if (!suspend_socket(sk, force_suspend))
  82                         active++;
  83         }
  84         return active;
  85 }
  86
  87 /* resume all suspended sockets in socket list */
  88 static void resume_socket_list(StatList *list)
  89 {
  90         List *item, *tmp;
  91         PgSocket *sk;
  92
  93         statlist_for_each_safe(item, list, tmp) {
  94                 sk = container_of(item, PgSocket, head);
  95                 if (sk->suspended) {
  96                         sk->suspended = 0;
  97                         sbuf_continue(&sk->sbuf);
  98                 }
  99         }
 100 }
 101
 102 /* resume all suspended sockets in all pools */
 103 static void resume_sockets(void)
 104 {
 105         List *item;
 106         PgPool *pool;
 107
 108         statlist_for_each(item, &pool_list) {
 109                 pool = container_of(item, PgPool, head);
 110                 if (pool->db->admin)
 111                         continue;
 112                 resume_socket_list(&pool->active_client_list);
 113                 resume_socket_list(&pool->active_server_list);
 114                 resume_socket_list(&pool->idle_server_list);
 115                 resume_socket_list(&pool->used_server_list);
 116         }
 117 }
 118
 119 /* resume pools and listen sockets */
 120 void resume_all(void)
 121 {
 122         resume_sockets();
 123         resume_pooler();
 124 }
 125
 126 /*
 127  * send test/reset query to server if needed
 128  */
 129 static void launch_recheck(PgPool *pool)
 130 {
 131         const char *q = cf_server_check_query;
 132         bool need_check = true;
 133         PgSocket *server;
 134         bool res = true;
 135
 136         /* find clean server */
 137         while (1) {
 138                 server = first_socket(&pool->used_server_list);
 139                 if (!server)
 140                         return;
 141                 if (server->ready)
 142                         break;
 143                 disconnect_server(server, true, "idle server got dirty");
 144         }
 145
 146         /* is the check needed? */
 147         if (q == NULL || q[0] == 0)
 148                 need_check = false;
 149         else if (cf_server_check_delay > 0) {
 150                 usec_t now = get_cached_time();
 151                 if (now - server->request_time < cf_server_check_delay)
 152                         need_check = false;
 153         }
 154
 155         if (need_check) {
 156                 /* send test query, wait for result */
 157                 slog_debug(server, "P: Checking: %s", q);
 158                 change_server_state(server, SV_TESTED);
 159                 SEND_generic(res, server, 'Q', "s", q);
 160                 if (!res)
 161                         disconnect_server(server, false, "test query failed");
 162         } else
 163                 /* make immediately available */
 164                 release_server(server);
 165 }
 166
 167 /*
 168  * make servers available
 169  */
 170 static void per_loop_activate(PgPool *pool)
 171 {
 172         List *item, *tmp;
 173         PgSocket *client;
 174
 175         /* see if any server have been freed */
 176         statlist_for_each_safe(item, &pool->waiting_client_list, tmp) {
 177                 client = container_of(item, PgSocket, head);
 178                 if (!statlist_empty(&pool->idle_server_list)) {
 179
 180                         /* db not fully initialized after reboot */
 181                         if (client->wait_for_welcome && !pool->welcome_msg_ready) {
 182                                 launch_new_connection(pool);
 183                                 continue;
 184                         }
 185
 186                         /* there is a ready server already */
 187                         activate_client(client);
 188                 } else if (!statlist_empty(&pool->tested_server_list)) {
 189                         /* some connections are in testing process */
 190                         break;
 191                 } else if (!statlist_empty(&pool->used_server_list)) {
 192                         /* ask for more connections to be tested */
 193                         launch_recheck(pool);
 194                         break;
 195                 } else {
 196                         /* not enough connections */
 197                         launch_new_connection(pool);
 198                         break;
 199                 }
 200         }
 201 }
 202
 203 /*
 204  * pause active clients
 205  */
 206 static int per_loop_pause(PgPool *pool)
 207 {
 208         int active = 0;
 209
 210         if (pool->db->admin)
 211                 return 0;
 212
 213         close_server_list(&pool->idle_server_list, "pause mode");
 214         close_server_list(&pool->used_server_list, "pause mode");
 215         close_server_list(&pool->new_server_list, "pause mode");
 216
 217         active += statlist_count(&pool->active_server_list);
 218         active += statlist_count(&pool->tested_server_list);
 219
 220         return active;
 221 }
 222
 223 /*
 224  * suspend active clients and servers
 225  */
 226 static int per_loop_suspend(PgPool *pool, bool force_suspend)
 227 {
 228         int active = 0;
 229
 230         if (pool->db->admin)
 231                 return 0;
 232
 233         active += suspend_socket_list(&pool->active_client_list, force_suspend);
 234
 235         /* this list is unsuspendable, but still need force_suspend and counting */
 236         active += suspend_socket_list(&pool->waiting_client_list, force_suspend);
 237         if (active)
 238                 per_loop_activate(pool);
 239
 240         if (!active) {
 241                 active += suspend_socket_list(&pool->active_server_list, force_suspend);
 242                 active += suspend_socket_list(&pool->idle_server_list, force_suspend);
 243
 244                 /* as all clients are done, no need for them */
 245                 close_server_list(&pool->tested_server_list, "close unsafe file descriptors on suspend");
 246                 close_server_list(&pool->used_server_list, "close unsafe file descriptors on suspend");
 247         }
 248
 249         return active;
 250 }
 251
 252 /*
 253  * this function is called for each event loop.
 254  */
 255 void per_loop_maint(void)
 256 {
 257         List *item;
 258         PgPool *pool;
 259         int active = 0;
 260         int partial_pause = 0;
 261         bool force_suspend = false;
 262
 263         if (cf_pause_mode == P_SUSPEND && cf_suspend_timeout > 0) {
 264                 usec_t stime = get_cached_time() - g_suspend_start;
 265                 if (stime >= cf_suspend_timeout)
 266                         force_suspend = true;
 267         }
 268
 269         statlist_for_each(item, &pool_list) {
 270                 pool = container_of(item, PgPool, head);
 271                 if (pool->db->admin)
 272                         continue;
 273                 switch (cf_pause_mode) {
 274                 case P_NONE:
 275                         if (pool->db->db_paused) {
 276                                 partial_pause = 1;
 277                                 active += per_loop_pause(pool);
 278                         } else
 279                                 per_loop_activate(pool);
 280                         break;
 281                 case P_PAUSE:
 282                         active += per_loop_pause(pool);
 283                         break;
 284                 case P_SUSPEND:
 285                         active += per_loop_suspend(pool, force_suspend);
 286                         break;
 287                 }
 288         }
 289
 290         switch (cf_pause_mode) {
 291         case P_SUSPEND:
 292                 if (force_suspend) {
 293                         close_client_list(&login_client_list, "suspend_timeout");
 294                 } else
 295                         active += statlist_count(&login_client_list);
 296         case P_PAUSE:
 297                 if (!active)
 298                         admin_pause_done();
 299                 break;
 300         case P_NONE:
 301                 if (partial_pause && !active)
 302                         admin_pause_done();
 303                 break;
 304         }
 305 }
 306
 307 /* maintaining clients in pool */
 308 static void pool_client_maint(PgPool *pool)
 309 {
 310         List *item, *tmp;
 311         usec_t now = get_cached_time();
 312         PgSocket *client;
 313         usec_t age;
 314
 315         /* force client_idle_timeout */
 316         if (cf_client_idle_timeout > 0) {
 317                 statlist_for_each_safe(item, &pool->active_client_list, tmp) {
 318                         client = container_of(item, PgSocket, head);
 319                         Assert(client->state == CL_ACTIVE);
 320                         if (client->link)
 321                                 continue;
 322                         if (now - client->request_time > cf_client_idle_timeout)
 323                                 disconnect_client(client, true, "client_idle_timeout");
 324                 }
 325         }
 326
 327         /* force timeouts for waiting queries */
 328         if (cf_query_timeout > 0 || cf_query_wait_timeout > 0) {
 329                 statlist_for_each_safe(item, &pool->waiting_client_list, tmp) {
 330                         client = container_of(item, PgSocket, head);
 331                         Assert(client->state == CL_WAITING);
 332                         if (client->query_start == 0) {
 333                                 age = now - client->request_time;
 334                                 //log_warning("query_start==0");
 335                         } else
 336                                 age = now - client->query_start;
 337
 338                         if (cf_query_timeout > 0 && age > cf_query_timeout)
 339                                 disconnect_client(client, true, "query_timeout");
 340                         else if (cf_query_wait_timeout > 0 && age > cf_query_wait_timeout)
 341                                 disconnect_client(client, true, "query_wait_timeout");
 342                 }
 343         }
 344
 345         /* apply client_login_timeout to clients waiting for welcome pkt */
 346         if (cf_client_login_timeout > 0 && !pool->welcome_msg_ready) {
 347                 statlist_for_each_safe(item, &pool->waiting_client_list, tmp) {
 348                         client = container_of(item, PgSocket, head);
 349                         age = now - client->connect_time;
 350                         if (!client->wait_for_welcome)
 351                                 continue;
 352                         if (age > cf_client_login_timeout)
 353                                 disconnect_client(client, true, "client_login_timeout (server down)");
 354                 }
 355         }
 356 }
 357
 358 static void check_unused_servers(PgPool *pool, StatList *slist, bool idle_test)
 359 {
 360         usec_t now = get_cached_time();
 361         List *item, *tmp;
 362         usec_t idle, age;
 363         PgSocket *server;
 364         usec_t lifetime_kill_gap = 0;
 365
 366         /*
 367          * Calculate the time that disconnects because of server_lifetime
 368          * must be separated.  This avoids the need to re-launch lot
 369          * of connections together.
 370          */
 371         if (pool->db->pool_size > 0)
 372                 lifetime_kill_gap = cf_server_lifetime / pool->db->pool_size;
 373
 374         /* disconnect idle servers if needed */
 375         statlist_for_each_safe(item, slist, tmp) {
 376                 server = container_of(item, PgSocket, head);
 377
 378                 age = now - server->connect_time;
 379                 idle = now - server->request_time;
 380
 381                 if (server->close_needed) {
 382                         disconnect_server(server, true, "database configuration changed");
 383                 } else if (server->state == SV_IDLE && !server->ready) {
 384                         disconnect_server(server, true, "SV_IDLE server got dirty");
 385                 } else if (server->state == SV_USED && !server->ready) {
 386                         disconnect_server(server, true, "SV_USED server got dirty");
 387                 } else if (cf_server_idle_timeout > 0 && idle > cf_server_idle_timeout) {
 388                         disconnect_server(server, true, "server idle timeout");
 389                 } else if (age >= cf_server_lifetime) {
 390                         if (pool->last_lifetime_disconnect + lifetime_kill_gap <= now) {
 391                                 disconnect_server(server, true, "server lifetime over");
 392                                 pool->last_lifetime_disconnect = now;
 393                         }
 394                 } else if (cf_pause_mode == P_PAUSE) {
 395                         disconnect_server(server, true, "pause mode");
 396                 } else if (idle_test && *cf_server_check_query) {
 397                         if (idle > cf_server_check_delay)
 398                                 change_server_state(server, SV_USED);
 399                 }
 400         }
 401 }
 402
 403 /*
 404  * Check pool size, close conns if too many.  Makes pooler
 405  * react faster to the case when admin decreased pool size.
 406  */
 407 static void check_pool_size(PgPool *pool)
 408 {
 409         PgSocket *server;
 410         int cur = statlist_count(&pool->active_server_list)
 411                 + statlist_count(&pool->idle_server_list)
 412                 + statlist_count(&pool->used_server_list)
 413                 + statlist_count(&pool->tested_server_list);
 414
 415                 /* cancel pkt may create new srv conn without
 416                  * taking pool_size into account
 417                  *
 418                  * statlist_count(&pool->new_server_list)
 419                  */
 420
 421         int many = cur - (pool->db->pool_size + pool->db->res_pool_size);
 422
 423         Assert(pool->db->pool_size >= 0);
 424
 425         while (many > 0) {
 426                 server = first_socket(&pool->used_server_list);
 427                 if (!server)
 428                         server = first_socket(&pool->idle_server_list);
 429                 if (!server)
 430                         break;
 431                 disconnect_server(server, true, "too many servers in the pool");
 432                 many--;
 433         }
 434 }
 435
 436 /* maintain servers in a pool */
 437 static void pool_server_maint(PgPool *pool)
 438 {
 439         List *item, *tmp;
 440         usec_t age, now = get_cached_time();
 441         PgSocket *server;
 442
 443         /* find and disconnect idle servers */
 444         check_unused_servers(pool, &pool->used_server_list, 0);
 445         check_unused_servers(pool, &pool->tested_server_list, 0);
 446         check_unused_servers(pool, &pool->idle_server_list, 1);
 447
 448         /* where query got did not get answer in query_timeout */
 449         if (cf_query_timeout > 0) {
 450                 statlist_for_each_safe(item, &pool->active_server_list, tmp) {
 451                         server = container_of(item, PgSocket, head);
 452                         Assert(server->state == SV_ACTIVE);
 453                         if (server->ready)
 454                                 continue;
 455                         age = now - server->link->request_time;
 456                         if (age > cf_query_timeout)
 457                                 disconnect_server(server, true, "query timeout");
 458                 }
 459         }
 460
 461         /* find connections that got connect, but could not log in */
 462         if (cf_server_connect_timeout > 0) {
 463                 statlist_for_each_safe(item, &pool->new_server_list, tmp) {
 464                         server = container_of(item, PgSocket, head);
 465                         Assert(server->state == SV_LOGIN);
 466
 467                         age = now - server->connect_time;
 468                         if (age > cf_server_connect_timeout)
 469                                 disconnect_server(server, true, "connect timeout");
 470                 }
 471         }
 472
 473         check_pool_size(pool);
 474 }
 475
 476 static void cleanup_client_logins(void)
 477 {
 478         List *item, *tmp;
 479         PgSocket *client;
 480         usec_t age;
 481         usec_t now = get_cached_time();
 482
 483         if (cf_client_login_timeout <= 0)
 484                 return;
 485
 486         statlist_for_each_safe(item, &login_client_list, tmp) {
 487                 client = container_of(item, PgSocket, head);
 488                 age = now - client->connect_time;
 489                 if (age > cf_client_login_timeout)
 490                         disconnect_client(client, true, "client_login_timeout");
 491         }
 492 }
 493
 494 static void kill_database(PgDatabase *db);
 495 static void cleanup_inactive_autodatabases(void)
 496 {
 497         List *item, *tmp;
 498         PgDatabase *db;
 499         usec_t age;
 500         usec_t now = get_cached_time();
 501
 502         if (cf_autodb_idle_timeout <= 0)
 503                 return;
 504
 505         statlist_for_each_safe(item, &autodatabase_idle_list, tmp) {
 506                 db = container_of(item, PgDatabase, head);
 507                 age = now - db->inactive_time;
 508                 if (age > cf_autodb_idle_timeout)
 509                         kill_database(db);
 510                 else
 511                         break;
 512         }
 513 }
 514
 515 /* full-scale maintenance, done only occasionally */
 516 static void do_full_maint(int sock, short flags, void *arg)
 517 {
 518         List *item, *tmp;
 519         PgPool *pool;
 520
 521         /*
 522          * Avoid doing anything that may surprise other pgbouncer.
 523          */
 524         if (cf_pause_mode == P_SUSPEND)
 525                 goto skip_maint;
 526
 527         statlist_for_each_safe(item, &pool_list, tmp) {
 528                 pool = container_of(item, PgPool, head);
 529                 if (pool->db->admin)
 530                         continue;
 531                 pool_server_maint(pool);
 532                 pool_client_maint(pool);
 533                 if (pool->db->db_auto && pool->db->inactive_time == 0 &&
 534                                 pool_client_count(pool) == 0 && pool_server_count(pool) == 0 ) {
 535                         pool->db->inactive_time = get_cached_time();
 536                         statlist_remove(&pool->db->head, &database_list);
 537                         statlist_append(&pool->db->head, &autodatabase_idle_list);
 538                 }
 539         }
 540
 541         cleanup_inactive_autodatabases();
 542
 543         cleanup_client_logins();
 544
 545         if (cf_shutdown == 1 && get_active_server_count() == 0) {
 546                 log_info("server connections dropped, exiting");
 547                 cf_shutdown = 2;
 548                 event_loopbreak();
 549                 return;
 550         }
 551
 552         if (cf_auth_type >= AUTH_TRUST)
 553                 loader_users_check();
 554
 555 skip_maint:
 556         safe_evtimer_add(&full_maint_ev, &full_maint_period);
 557 }
 558
 559 /* first-time initializtion */
 560 void janitor_setup(void)
 561 {
 562         /* launch maintenance */
 563         evtimer_set(&full_maint_ev, do_full_maint, NULL);
 564         safe_evtimer_add(&full_maint_ev, &full_maint_period);
 565 }
 566
 567 static void kill_pool(PgPool *pool)
 568 {
 569         const char *reason = "database removed";
 570
 571         close_client_list(&pool->active_client_list, reason);
 572         close_client_list(&pool->waiting_client_list, reason);
 573         close_client_list(&pool->cancel_req_list, reason);
 574
 575         close_server_list(&pool->active_server_list, reason);
 576         close_server_list(&pool->idle_server_list, reason);
 577         close_server_list(&pool->used_server_list, reason);
 578         close_server_list(&pool->tested_server_list, reason);
 579         close_server_list(&pool->new_server_list, reason);
 580
 581         list_del(&pool->map_head);
 582         statlist_remove(&pool->head, &pool_list);
 583         obj_free(pool_cache, pool);
 584 }
 585
 586 static void kill_database(PgDatabase *db)
 587 {
 588         PgPool *pool;
 589         List *item, *tmp;
 590
 591         log_warning("dropping database '%s' as it does not exist anymore or inactive auto-database", db->name);
 592
 593         statlist_for_each_safe(item, &pool_list, tmp) {
 594                 pool = container_of(item, PgPool, head);
 595                 if (pool->db == db)
 596                         kill_pool(pool);
 597         }
 598         if (db->forced_user)
 599                 obj_free(user_cache, db->forced_user);
 600         if (db->connect_query)
 601                 free((void *)db->connect_query);
 602         if (db->inactive_time)
 603                 statlist_remove(&db->head, &autodatabase_idle_list);
 604         else
 605                 statlist_remove(&db->head, &database_list);
 606         obj_free(db_cache, db);
 607 }
 608
 609 /* as [pgbouncer] section can be loaded after databases,
 610    there's need for review */
 611 void config_postprocess(void)
 612 {
 613         List *item, *tmp;
 614         PgDatabase *db;
 615
 616         statlist_for_each_safe(item, &database_list, tmp) {
 617                 db = container_of(item, PgDatabase, head);
 618                 if (db->db_dead) {
 619                         kill_database(db);
 620                         continue;
 621                 }
 622                 if (db->pool_size < 0)
 623                         db->pool_size = cf_default_pool_size;
 624                 if (db->res_pool_size < 0)
 625                         db->res_pool_size = cf_res_pool_size;
 626         }
 627 }
 628