src/slowlog.c

   1 #include "redis.h"
   2 #include "slowlog.h"
   3
   4 /* Slowlog implements a system that is able to remember the latest N
   5  * queries that took more than M microseconds to execute.
   6  *
   7  * The execution time to reach to be logged in the slow log is set
   8  * using the 'slowlog-log-slower-than' config directive, that is also
   9  * readable and writable using the CONFIG SET/GET command.
  10  *
  11  * The slow queries log is actually not "logged" in the Redis log file
  12  * but is accessible thanks to the SLOWLOG command. */
  13
  14 /* Create a new slowlog entry.
  15  * Incrementing the ref count of all the objects retained is up to
  16  * this function. */
  17 slowlogEntry *slowlogCreateEntry(robj **argv, int argc, long long duration) {
  18     slowlogEntry *se = zmalloc(sizeof(*se));
  19     int j;
  20
  21     se->argc = argc;
  22     se->argv = zmalloc(sizeof(robj*)*argc);
  23     for (j = 0; j < argc; j++) {
  24         se->argv[j] = argv[j];
  25         incrRefCount(argv[j]);
  26     }
  27     se->time = time(NULL);
  28     se->duration = duration;
  29     return se;
  30 }
  31
  32 /* Free a slow log entry. The argument is void so that the prototype of this
  33  * function matches the one of the 'free' method of adlist.c.
  34  *
  35  * This function will take care to release all the retained object. */
  36 void slowlogFreeEntry(void *septr) {
  37     slowlogEntry *se = septr;
  38     int j;
  39
  40     for (j = 0; j < se->argc; j++)
  41         decrRefCount(se->argv[j]);
  42     zfree(se->argv);
  43     zfree(se);
  44 }
  45
  46 /* Initialize the slow log. This function should be called a single time
  47  * at server startup. */
  48 void slowlogInit(void) {
  49     server.slowlog = listCreate();
  50     listSetFreeMethod(server.slowlog,slowlogFreeEntry);
  51 }
  52
  53 /* Push a new entry into the slow log.
  54  * This function will make sure to trim the slow log accordingly to the
  55  * configured max length. */
  56 void slowlogPushEntryIfNeeded(robj **argv, int argc, long long duration) {
  57     if (server.slowlog_log_slower_than < 0) return; /* Slowlog disabled */
  58     if (duration >= server.slowlog_log_slower_than)
  59         listAddNodeHead(server.slowlog,slowlogCreateEntry(argv,argc,duration));
  60
  61     /* Remove old entries if needed. */
  62     while (listLength(server.slowlog) > server.slowlog_max_len)
  63         listDelNode(server.slowlog,listLast(server.slowlog));
  64 }
  65
  66 /* Remove all the entries from the current slow log. */
  67 void slowlogReset(void) {
  68     while (listLength(server.slowlog) > 0)
  69         listDelNode(server.slowlog,listLast(server.slowlog));
  70 }
  71
  72 /* The SLOWLOG command. Implements all the subcommands needed to handle the
  73  * Redis slow log. */
  74 void slowlogCommand(redisClient *c) {
  75     if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"reset")) {
  76         slowlogReset();
  77         addReply(c,shared.ok);
  78     } else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"len")) {
  79         addReplyLongLong(c,listLength(server.slowlog));
  80     } else if ((c->argc == 2 || c->argc == 3) &&
  81                !strcasecmp(c->argv[1]->ptr,"get"))
  82     {
  83         long count = 10, sent = 0;
  84         listIter li;
  85         void *totentries;
  86         listNode *ln;
  87         slowlogEntry *se;
  88
  89         if (c->argc == 3 &&
  90             getLongFromObjectOrReply(c,c->argv[2],&count,NULL) != REDIS_OK)
  91             return;
  92
  93         listRewind(server.slowlog,&li);
  94         totentries = addDeferredMultiBulkLength(c);
  95         while(count-- && (ln = listNext(&li))) {
  96             int j;
  97
  98             se = ln->value;
  99             addReplyMultiBulkLen(c,3);
 100             addReplyLongLong(c,se->time);
 101             addReplyLongLong(c,se->duration);
 102             addReplyMultiBulkLen(c,se->argc);
 103             for (j = 0; j < se->argc; j++)
 104                 addReplyBulk(c,se->argv[j]);
 105             sent++;
 106         }
 107         setDeferredMultiBulkLength(c,totentries,sent);
 108     } else {
 109         addReplyError(c,
 110             "Unknown SLOWLOG subcommand or wrong # of args. Try GET, RESET, LEN.");
 111     }
 112 }