NAME

       mysqld_qslower - Trace MySQL server queries slower than a threshold.

SYNOPSIS

       mysqld_qslower PID [min_ms]

DESCRIPTION

       This  traces  queries  served  by  a  MySQL  server, and prints those that exceed a custom
       latency (query duration) threshold. By default, a minimum threshold of  1  millisecond  is
       used. If a threshold of 0 is used, all queries are printed.

       This  uses  User  Statically-Defined  Tracing  (USDT) probes, a feature added to MySQL for
       DTrace support, but  which  may  not  be  enabled  on  a  given  MySQL  installation.  See
       requirements.

       Since this uses BPF, only the root user can use this tool.

REQUIREMENTS

       CONFIG_BPF,  bcc,  and  MySQL  server with USDT probe support (when configuring the build:
       -DENABLE_DTRACE=1).

OPTIONS

       PID Trace this mysqld PID.

       min_ms Minimum query latency (duration) to trace, in milliseconds. Default is 1 ms.

EXAMPLES

       Trace MySQL server queries slower than 1 ms for PID 1981:
              # mysqld_qslower 1981

       Trace slower than 10 ms for PID 1981:
              # mysqld_qslower 1981 10

FIELDS

       TIME(s)
              Time of query start, in seconds.

       PID    Process ID of the traced server.

       MS     Milliseconds for the query, from start to end.

       QUERY  Query string, truncated to 128 characters.

OVERHEAD

       This adds low-overhead instrumentation to MySQL queries, and only emits output  data  from
       kernel to user-level if they query exceeds the threshold. If the server query rate is less
       than 1,000/sec, the overhead is expected to be negligible. If the query  rate  is  higher,
       test to gauge overhead.

SOURCE

       This is from bcc.

              https://github.com/iovisor/bcc

       Also  look  in  the bcc distribution for a companion _examples.txt file containing example
       usage, output, and commentary for this tool.

OS

       Linux

STABILITY

       Unstable - in development.

AUTHOR

       Brendan Gregg

SEE ALSO

       biosnoop(8)