monitor.3valkey - Man Page
Listens for all requests received by the server in real-time.
Synopsis
MONITOR
Description
MONITOR is a debugging command that streams back every command processed by the Valkey server. It can help in understanding what is happening to the database. This command can both be used via valkey-cli and via telnet.
The ability to see all the requests processed by the server is useful in order to spot bugs in an application both when using Valkey as a database and as a distributed caching system.
$ valkey-cli monitor
1339518083.107412 [0 127.0.0.1:60866] "keys" "*"
1339518087.877697 [0 127.0.0.1:60866] "dbsize"
1339518090.420270 [0 127.0.0.1:60866] "set" "x" "6"
1339518096.506257 [0 127.0.0.1:60866] "get" "x"
1339518099.363765 [0 127.0.0.1:60866] "eval" "return server.call('set','x','7')" "0"
1339518100.363799 [0 lua] "set" "x" "7"
1339518100.544926 [0 127.0.0.1:60866] "del" "x"Use SIGINT (Ctrl-C) to stop a MONITOR stream running via valkey-cli.
$ telnet localhost 6379 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. MONITOR +OK +1339518083.107412 [0 127.0.0.1:60866] "keys" "*" +1339518087.877697 [0 127.0.0.1:60866] "dbsize" +1339518090.420270 [0 127.0.0.1:60866] "set" "x" "6" +1339518096.506257 [0 127.0.0.1:60866] "get" "x" +1339518099.363765 [0 127.0.0.1:60866] "del" "x" +1339518100.544926 [0 127.0.0.1:60866] "get" "x" QUIT +OK Connection closed by foreign host.
Manually issue the QUIT or RESET commands to stop a MONITOR stream running via telnet.
Commands not logged by MONITOR
Because of security concerns, no administrative commands are logged by MONITOR’s output and sensitive data is redacted in the command AUTH.
Furthermore, the command QUIT is also not logged.
Cost of running MONITOR
Because MONITOR streams back all commands, its use comes at a cost. The following (totally unscientific) benchmark numbers illustrate what the cost of running MONITOR can be.
Benchmark result without MONITOR running:
$ src/valkey-benchmark -c 10 -n 100000 -q PING_INLINE: 101936.80 requests per second PING_BULK: 102880.66 requests per second SET: 95419.85 requests per second GET: 104275.29 requests per second INCR: 93283.58 requests per second
Benchmark result with MONITOR running (valkey-cli monitor > /dev/null):
$ src/valkey-benchmark -c 10 -n 100000 -q PING_INLINE: 58479.53 requests per second PING_BULK: 59136.61 requests per second SET: 41823.50 requests per second GET: 45330.91 requests per second INCR: 41771.09 requests per second
In this particular case, running a single MONITOR client can reduce the throughput by more than 50%. Running more MONITOR clients will reduce throughput even more.
Note that, * AUTH is excluded from the command’s output. * RESET can be called to exit monitor mode. * AUTH, HELLO, EVAL, EVAL_RO, EVALSHA and EVALSHA_RO are included in the command’s output.
Reply
Non-standard return value. Dumps the received commands in an infinite flow.
Acl Categories
@admin @dangerous @slow
History
- Available since: 1.0.0
See Also
acl(3valkey), acl-cat(3valkey), acl-deluser(3valkey), acl-dryrun(3valkey), acl-genpass(3valkey), acl-getuser(3valkey), acl-help(3valkey), acl-list(3valkey), acl-load(3valkey), acl-log(3valkey), acl-save(3valkey), acl-setuser(3valkey), acl-users(3valkey), acl-whoami(3valkey), bgrewriteaof(3valkey), bgsave(3valkey), command(3valkey), command-count(3valkey), command-docs(3valkey), command-getkeys(3valkey), command-getkeysandflags(3valkey), command-help(3valkey), command-info(3valkey), command-list(3valkey), config(3valkey), config-get(3valkey), config-help(3valkey), config-resetstat(3valkey), config-rewrite(3valkey), config-set(3valkey), dbsize(3valkey), debug(3valkey), failover(3valkey), flushall(3valkey), flushdb(3valkey), info(3valkey), lastsave(3valkey), latency(3valkey), latency-doctor(3valkey), latency-graph(3valkey), latency-help(3valkey), latency-histogram(3valkey), latency-history(3valkey), latency-latest(3valkey), latency-reset(3valkey), lolwut(3valkey), memory(3valkey), memory-doctor(3valkey), memory-help(3valkey), memory-malloc-stats(3valkey), memory-purge(3valkey), memory-stats(3valkey), memory-usage(3valkey), module(3valkey), module-help(3valkey), module-list(3valkey), module-load(3valkey), module-loadex(3valkey), module-unload(3valkey), psync(3valkey), replconf(3valkey), replicaof(3valkey), restore-asking(3valkey), role(3valkey), save(3valkey), shutdown(3valkey), slowlog(3valkey), slowlog-get(3valkey), slowlog-help(3valkey), slowlog-len(3valkey), slowlog-reset(3valkey), swapdb(3valkey), sync(3valkey), time(3valkey)