---
name: "mysqld_qslower-bpfcc"
section: "8"
platform: "linux"
package: "bpfcc-tools"
version: "0.31.0+ds-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mysqld_qslower-bpfcc"
---

# mysqld\_qslower-bpfcc(8)

Trace MySQL server queries slower than a threshold.

## 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)