server/scoreboard.c

   1 /* Licensed to the Apache Software Foundation (ASF) under one or more
   2  * contributor license agreements.  See the NOTICE file distributed with
   3  * this work for additional information regarding copyright ownership.
   4  * The ASF licenses this file to You under the Apache License, Version 2.0
   5  * (the "License"); you may not use this file except in compliance with
   6  * the License.  You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "apr.h"
  18 #include "apr_strings.h"
  19 #include "apr_portable.h"
  20 #include "apr_lib.h"
  21
  22 #define APR_WANT_STRFUNC
  23 #include "apr_want.h"
  24
  25 #if APR_HAVE_SYS_TYPES_H
  26 #include <sys/types.h>
  27 #endif
  28
  29 #include "ap_config.h"
  30 #include "httpd.h"
  31 #include "http_log.h"
  32 #include "http_main.h"
  33 #include "http_core.h"
  34 #include "http_config.h"
  35 #include "ap_mpm.h"
  36
  37 #include "mpm.h"
  38 #include "scoreboard.h"
  39
  40 AP_DECLARE_DATA scoreboard *ap_scoreboard_image = NULL;
  41 AP_DECLARE_DATA const char *ap_scoreboard_fname = NULL;
  42 AP_DECLARE_DATA int ap_extended_status = 0;
  43 AP_DECLARE_DATA int ap_mod_status_reqtail = 0;
  44
  45 #if APR_HAS_SHARED_MEMORY
  46
  47 #include "apr_shm.h"
  48
  49 #ifndef WIN32
  50 static /* but must be exported to mpm_winnt */
  51 #endif
  52         apr_shm_t *ap_scoreboard_shm = NULL;
  53
  54 #endif
  55
  56 APR_HOOK_STRUCT(
  57     APR_HOOK_LINK(pre_mpm)
  58 )
  59
  60 AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_mpm,
  61                           (apr_pool_t *p, ap_scoreboard_e sb_type),
  62                           (p, sb_type),OK,DECLINED)
  63
  64 static APR_OPTIONAL_FN_TYPE(ap_proxy_lb_workers)
  65                                 *pfn_proxy_lb_workers;
  66 static APR_OPTIONAL_FN_TYPE(ap_proxy_lb_worker_size)
  67                                 *pfn_proxy_lb_worker_size;
  68
  69 struct ap_sb_handle_t {
  70     int child_num;
  71     int thread_num;
  72 };
  73
  74 static int server_limit, thread_limit, lb_limit, lb_size;
  75 static apr_size_t scoreboard_size;
  76
  77 /*
  78  * ToDo:
  79  * This function should be renamed to cleanup_shared
  80  * and it should handle cleaning up a scoreboard shared
  81  * between processes using any form of IPC (file, shared memory
  82  * segment, etc.). Leave it as is now because it is being used
  83  * by various MPMs.
  84  */
  85 static apr_status_t ap_cleanup_shared_mem(void *d)
  86 {
  87 #if APR_HAS_SHARED_MEMORY
  88     free(ap_scoreboard_image);
  89     ap_scoreboard_image = NULL;
  90     apr_shm_destroy(ap_scoreboard_shm);
  91 #endif
  92     return APR_SUCCESS;
  93 }
  94
  95 AP_DECLARE(int) ap_calc_scoreboard_size(void)
  96 {
  97     ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &thread_limit);
  98     ap_mpm_query(AP_MPMQ_HARD_LIMIT_DAEMONS, &server_limit);
  99
 100     if (!pfn_proxy_lb_workers)
 101         pfn_proxy_lb_workers = APR_RETRIEVE_OPTIONAL_FN(ap_proxy_lb_workers);
 102     if (pfn_proxy_lb_workers)
 103         lb_limit = pfn_proxy_lb_workers();
 104     else
 105         lb_limit = 0;
 106
 107     if (!pfn_proxy_lb_worker_size)
 108         pfn_proxy_lb_worker_size = APR_RETRIEVE_OPTIONAL_FN(ap_proxy_lb_worker_size);
 109     if (pfn_proxy_lb_worker_size)
 110         lb_size = pfn_proxy_lb_worker_size();
 111     else
 112         lb_size = sizeof(lb_score);
 113
 114     scoreboard_size = sizeof(global_score);
 115     scoreboard_size += sizeof(process_score) * server_limit;
 116     scoreboard_size += sizeof(worker_score) * server_limit * thread_limit;
 117     if (lb_limit && lb_size)
 118         scoreboard_size += lb_size * lb_limit;
 119
 120     return scoreboard_size;
 121 }
 122
 123 void ap_init_scoreboard(void *shared_score)
 124 {
 125     char *more_storage;
 126     int i;
 127
 128     ap_calc_scoreboard_size();
 129     ap_scoreboard_image =
 130         calloc(1, sizeof(scoreboard) + server_limit * sizeof(worker_score *));
 131     more_storage = shared_score;
 132     ap_scoreboard_image->global = (global_score *)more_storage;
 133     more_storage += sizeof(global_score);
 134     ap_scoreboard_image->parent = (process_score *)more_storage;
 135     more_storage += sizeof(process_score) * server_limit;
 136     ap_scoreboard_image->servers =
 137         (worker_score **)((char*)ap_scoreboard_image + sizeof(scoreboard));
 138     for (i = 0; i < server_limit; i++) {
 139         ap_scoreboard_image->servers[i] = (worker_score *)more_storage;
 140         more_storage += thread_limit * sizeof(worker_score);
 141     }
 142     if (lb_limit && lb_size) {
 143         ap_scoreboard_image->balancers = (void *)more_storage;
 144         more_storage += lb_limit * lb_size;
 145     }
 146     ap_assert(more_storage == (char*)shared_score + scoreboard_size);
 147     ap_scoreboard_image->global->server_limit = server_limit;
 148     ap_scoreboard_image->global->thread_limit = thread_limit;
 149     ap_scoreboard_image->global->lb_limit     = lb_limit;
 150 }
 151
 152 /**
 153  * Create a name-based scoreboard in the given pool using the
 154  * given filename.
 155  */
 156 static apr_status_t create_namebased_scoreboard(apr_pool_t *pool,
 157                                                 const char *fname)
 158 {
 159 #if APR_HAS_SHARED_MEMORY
 160     apr_status_t rv;
 161
 162     /* The shared memory file must not exist before we create the
 163      * segment. */
 164     apr_shm_remove(fname, pool); /* ignore errors */
 165
 166     rv = apr_shm_create(&ap_scoreboard_shm, scoreboard_size, fname, pool);
 167     if (rv != APR_SUCCESS) {
 168         ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
 169                      "unable to create or access scoreboard \"%s\" "
 170                      "(name-based shared memory failure)", fname);
 171         return rv;
 172     }
 173 #endif /* APR_HAS_SHARED_MEMORY */
 174     return APR_SUCCESS;
 175 }
 176
 177 /* ToDo: This function should be made to handle setting up
 178  * a scoreboard shared between processes using any IPC technique,
 179  * not just a shared memory segment
 180  */
 181 static apr_status_t open_scoreboard(apr_pool_t *pconf)
 182 {
 183 #if APR_HAS_SHARED_MEMORY
 184     apr_status_t rv;
 185     char *fname = NULL;
 186     apr_pool_t *global_pool;
 187
 188     /* We don't want to have to recreate the scoreboard after
 189      * restarts, so we'll create a global pool and never clean it.
 190      */
 191     rv = apr_pool_create(&global_pool, NULL);
 192     if (rv != APR_SUCCESS) {
 193         ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
 194                      "Fatal error: unable to create global pool "
 195                      "for use by the scoreboard");
 196         return rv;
 197     }
 198
 199     /* The config says to create a name-based shmem */
 200     if (ap_scoreboard_fname) {
 201         /* make sure it's an absolute pathname */
 202         fname = ap_server_root_relative(pconf, ap_scoreboard_fname);
 203         if (!fname) {
 204             ap_log_error(APLOG_MARK, APLOG_CRIT, APR_EBADPATH, NULL,
 205                          "Fatal error: Invalid Scoreboard path %s",
 206                          ap_scoreboard_fname);
 207             return APR_EBADPATH;
 208         }
 209         return create_namebased_scoreboard(global_pool, fname);
 210     }
 211     else { /* config didn't specify, we get to choose shmem type */
 212         rv = apr_shm_create(&ap_scoreboard_shm, scoreboard_size, NULL,
 213                             global_pool); /* anonymous shared memory */
 214         if ((rv != APR_SUCCESS) && (rv != APR_ENOTIMPL)) {
 215             ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
 216                          "Unable to create or access scoreboard "
 217                          "(anonymous shared memory failure)");
 218             return rv;
 219         }
 220         /* Make up a filename and do name-based shmem */
 221         else if (rv == APR_ENOTIMPL) {
 222             /* Make sure it's an absolute pathname */
 223             ap_scoreboard_fname = DEFAULT_SCOREBOARD;
 224             fname = ap_server_root_relative(pconf, ap_scoreboard_fname);
 225
 226             return create_namebased_scoreboard(global_pool, fname);
 227         }
 228     }
 229 #endif /* APR_HAS_SHARED_MEMORY */
 230     return APR_SUCCESS;
 231 }
 232
 233 /* If detach is non-zero, this is a seperate child process,
 234  * if zero, it is a forked child.
 235  */
 236 apr_status_t ap_reopen_scoreboard(apr_pool_t *p, apr_shm_t **shm, int detached)
 237 {
 238 #if APR_HAS_SHARED_MEMORY
 239     if (!detached) {
 240         return APR_SUCCESS;
 241     }
 242     if (apr_shm_size_get(ap_scoreboard_shm) < scoreboard_size) {
 243         ap_log_error(APLOG_MARK, APLOG_CRIT, 0, NULL,
 244                      "Fatal error: shared scoreboard too small for child!");
 245         apr_shm_detach(ap_scoreboard_shm);
 246         ap_scoreboard_shm = NULL;
 247         return APR_EINVAL;
 248     }
 249     /* everything will be cleared shortly */
 250     if (*shm) {
 251         *shm = ap_scoreboard_shm;
 252     }
 253 #endif
 254     return APR_SUCCESS;
 255 }
 256
 257 apr_status_t ap_cleanup_scoreboard(void *d)
 258 {
 259     if (ap_scoreboard_image == NULL) {
 260         return APR_SUCCESS;
 261     }
 262     if (ap_scoreboard_image->global->sb_type == SB_SHARED) {
 263         ap_cleanup_shared_mem(NULL);
 264     }
 265     else {
 266         free(ap_scoreboard_image->global);
 267         free(ap_scoreboard_image);
 268         ap_scoreboard_image = NULL;
 269     }
 270     return APR_SUCCESS;
 271 }
 272
 273 /* Create or reinit an existing scoreboard. The MPM can control whether
 274  * the scoreboard is shared across multiple processes or not
 275  */
 276 int ap_create_scoreboard(apr_pool_t *p, ap_scoreboard_e sb_type)
 277 {
 278     int running_gen = 0;
 279     int i;
 280 #if APR_HAS_SHARED_MEMORY
 281     apr_status_t rv;
 282 #endif
 283
 284     if (ap_scoreboard_image) {
 285         running_gen = ap_scoreboard_image->global->running_generation;
 286         ap_scoreboard_image->global->restart_time = apr_time_now();
 287         memset(ap_scoreboard_image->parent, 0,
 288                sizeof(process_score) * server_limit);
 289         for (i = 0; i < server_limit; i++) {
 290             memset(ap_scoreboard_image->servers[i], 0,
 291                    sizeof(worker_score) * thread_limit);
 292         }
 293         /* Clean up the lb workers data */
 294         if (lb_limit && lb_size) {
 295             memset(ap_scoreboard_image->balancers, 0,
 296                    lb_size * lb_limit);
 297         }
 298         return OK;
 299     }
 300
 301     ap_calc_scoreboard_size();
 302 #if APR_HAS_SHARED_MEMORY
 303     if (sb_type == SB_SHARED) {
 304         void *sb_shared;
 305         rv = open_scoreboard(p);
 306         if (rv || !(sb_shared = apr_shm_baseaddr_get(ap_scoreboard_shm))) {
 307             return HTTP_INTERNAL_SERVER_ERROR;
 308         }
 309         memset(sb_shared, 0, scoreboard_size);
 310         ap_init_scoreboard(sb_shared);
 311     }
 312     else
 313 #endif
 314     {
 315         /* A simple malloc will suffice */
 316         void *sb_mem = calloc(1, scoreboard_size);
 317         if (sb_mem == NULL) {
 318             ap_log_error(APLOG_MARK, APLOG_CRIT, 0, NULL,
 319                          "(%d)%s: cannot allocate scoreboard",
 320                          errno, strerror(errno));
 321             return HTTP_INTERNAL_SERVER_ERROR;
 322         }
 323         ap_init_scoreboard(sb_mem);
 324     }
 325
 326     ap_scoreboard_image->global->sb_type = sb_type;
 327     ap_scoreboard_image->global->running_generation = running_gen;
 328     ap_scoreboard_image->global->restart_time = apr_time_now();
 329
 330     apr_pool_cleanup_register(p, NULL, ap_cleanup_scoreboard, apr_pool_cleanup_null);
 331
 332     return OK;
 333 }
 334
 335 /* Routines called to deal with the scoreboard image
 336  * --- note that we do *not* need write locks, since update_child_status
 337  * only updates a *single* record in place, and only one process writes to
 338  * a given scoreboard slot at a time (either the child process owning that
 339  * slot, or the parent, noting that the child has died).
 340  *
 341  * As a final note --- setting the score entry to getpid() is always safe,
 342  * since when the parent is writing an entry, it's only noting SERVER_DEAD
 343  * anyway.
 344  */
 345
 346 AP_DECLARE(int) ap_exists_scoreboard_image(void)
 347 {
 348     return (ap_scoreboard_image ? 1 : 0);
 349 }
 350
 351 AP_DECLARE(void) ap_increment_counts(ap_sb_handle_t *sb, request_rec *r)
 352 {
 353     worker_score *ws;
 354
 355     if (!sb)
 356         return;
 357
 358     ws = &ap_scoreboard_image->servers[sb->child_num][sb->thread_num];
 359
 360 #ifdef HAVE_TIMES
 361     times(&ws->times);
 362 #endif
 363     ws->access_count++;
 364     ws->my_access_count++;
 365     ws->conn_count++;
 366     ws->bytes_served += r->bytes_sent;
 367     ws->my_bytes_served += r->bytes_sent;
 368     ws->conn_bytes += r->bytes_sent;
 369 }
 370
 371 AP_DECLARE(int) ap_find_child_by_pid(apr_proc_t *pid)
 372 {
 373     int i;
 374     int max_daemons_limit;
 375
 376     ap_mpm_query(AP_MPMQ_MAX_DAEMONS, &max_daemons_limit);
 377
 378     for (i = 0; i < max_daemons_limit; ++i) {
 379         if (ap_scoreboard_image->parent[i].pid == pid->pid) {
 380             return i;
 381         }
 382     }
 383
 384     return -1;
 385 }
 386
 387 AP_DECLARE(void) ap_create_sb_handle(ap_sb_handle_t **new_sbh, apr_pool_t *p,
 388                                      int child_num, int thread_num)
 389 {
 390     *new_sbh = (ap_sb_handle_t *)apr_palloc(p, sizeof(ap_sb_handle_t));
 391     (*new_sbh)->child_num = child_num;
 392     (*new_sbh)->thread_num = thread_num;
 393 }
 394
 395 static void copy_request(char *rbuf, apr_size_t rbuflen, request_rec *r)
 396 {
 397     char *p;
 398
 399     if (r->the_request == NULL) {
 400         apr_cpystrn(rbuf, "NULL", rbuflen);
 401         return; /* short circuit below */
 402     }
 403
 404     if (r->parsed_uri.password == NULL) {
 405         p = r->the_request;
 406     }
 407     else {
 408         /* Don't reveal the password in the server-status view */
 409         p = apr_pstrcat(r->pool, r->method, " ",
 410                         apr_uri_unparse(r->pool, &r->parsed_uri,
 411                         APR_URI_UNP_OMITPASSWORD),
 412                         r->assbackwards ? NULL : " ", r->protocol, NULL);
 413     }
 414
 415     /* now figure out if we copy over the 1st rbuflen chars or the last */
 416     if (!ap_mod_status_reqtail) {
 417         apr_cpystrn(rbuf, p, rbuflen);
 418     }
 419     else {
 420         apr_size_t slen = strlen(p);
 421         if (slen < rbuflen) {
 422             /* it all fits anyway */
 423             apr_cpystrn(rbuf, p, rbuflen);
 424         }
 425         else {
 426             apr_cpystrn(rbuf, p+(slen-rbuflen+1), rbuflen);
 427         }
 428     }
 429 }
 430
 431 AP_DECLARE(int) ap_update_child_status_from_indexes(int child_num,
 432                                                     int thread_num,
 433                                                     int status,
 434                                                     request_rec *r)
 435 {
 436     int old_status;
 437     worker_score *ws;
 438     process_score *ps;
 439
 440     if (child_num < 0) {
 441         return -1;
 442     }
 443
 444     ws = &ap_scoreboard_image->servers[child_num][thread_num];
 445     old_status = ws->status;
 446     ws->status = status;
 447
 448     ps = &ap_scoreboard_image->parent[child_num];
 449
 450     if (status == SERVER_READY
 451         && old_status == SERVER_STARTING) {
 452         ws->thread_num = child_num * thread_limit + thread_num;
 453         ps->generation = ap_my_generation;
 454     }
 455
 456     if (ap_extended_status) {
 457         ws->last_used = apr_time_now();
 458         if (status == SERVER_READY || status == SERVER_DEAD) {
 459             /*
 460              * Reset individual counters
 461              */
 462             if (status == SERVER_DEAD) {
 463                 ws->my_access_count = 0L;
 464                 ws->my_bytes_served = 0L;
 465             }
 466             ws->conn_count = 0;
 467             ws->conn_bytes = 0;
 468         }
 469         if (r) {
 470             conn_rec *c = r->connection;
 471             apr_cpystrn(ws->client, ap_get_remote_host(c, r->per_dir_config,
 472                         REMOTE_NOLOOKUP, NULL), sizeof(ws->client));
 473             copy_request(ws->request, sizeof(ws->request), r);
 474             apr_cpystrn(ws->vhost, r->server->server_hostname,
 475                         sizeof(ws->vhost));
 476         }
 477     }
 478
 479     return old_status;
 480 }
 481
 482 AP_DECLARE(int) ap_update_child_status(ap_sb_handle_t *sbh, int status,
 483                                       request_rec *r)
 484 {
 485     if (!sbh)
 486         return -1;
 487
 488     return ap_update_child_status_from_indexes(sbh->child_num, sbh->thread_num,
 489                                                status, r);
 490 }
 491
 492 AP_DECLARE(void) ap_time_process_request(ap_sb_handle_t *sbh, int status)
 493 {
 494     worker_score *ws;
 495
 496     if (!sbh)
 497         return;
 498
 499     if (sbh->child_num < 0) {
 500         return;
 501     }
 502
 503     ws = &ap_scoreboard_image->servers[sbh->child_num][sbh->thread_num];
 504
 505     if (status == START_PREQUEST) {
 506         ws->start_time = apr_time_now();
 507     }
 508     else if (status == STOP_PREQUEST) {
 509         ws->stop_time = apr_time_now();
 510     }
 511 }
 512
 513 AP_DECLARE(worker_score *) ap_get_scoreboard_worker_from_indexes(int x, int y)
 514 {
 515     if (((x < 0) || (x >= server_limit)) ||
 516         ((y < 0) || (y >= thread_limit))) {
 517         return(NULL); /* Out of range */
 518     }
 519     return &ap_scoreboard_image->servers[x][y];
 520 }
 521
 522 AP_DECLARE(worker_score *) ap_get_scoreboard_worker(ap_sb_handle_t *sbh)
 523 {
 524     if (!sbh)
 525         return NULL;
 526
 527     return ap_get_scoreboard_worker_from_indexes(sbh->child_num,
 528                                                  sbh->thread_num);
 529 }
 530
 531 AP_DECLARE(process_score *) ap_get_scoreboard_process(int x)
 532 {
 533     if ((x < 0) || (x >= server_limit)) {
 534         return(NULL); /* Out of range */
 535     }
 536     return &ap_scoreboard_image->parent[x];
 537 }
 538
 539 AP_DECLARE(global_score *) ap_get_scoreboard_global()
 540 {
 541     return ap_scoreboard_image->global;
 542 }
 543
 544 AP_DECLARE(lb_score *) ap_get_scoreboard_lb(int lb_num)
 545 {
 546     if ( (lb_num < 0) || (lb_limit < lb_num) || (lb_size==0) ) {
 547         return(NULL); /* Out of range */
 548     }
 549     return (lb_score *) ( ((char *) ap_scoreboard_image->balancers) +
 550                           (lb_num*lb_size) );
 551 }