---
name: "dbslower-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/dbslower-bpfcc"
---

# dbslower-bpfcc(8)

Trace MySQL/PostgreSQL server queries slower than a threshold.

## NAME

dbslower - Trace MySQL/PostgreSQL server queries slower than a threshold.

## SYNOPSIS

**dbslower \[-v\] \[-p PID \[PID ...\]\] \[-x PATH\] \[-m THRESHOLD\] {mysql,postgres}**

## DESCRIPTION

This traces queries served by a MySQL or PostgreSQL server, and prints those that exceed a latency (query time) threshold. By default a threshold of 1 ms is used.

This uses User Statically-Defined Tracing (USDT) probes, a feature added to MySQL and PostgreSQL for DTrace support, but which may not be enabled on a given installation. See requirements. Alternatively, MySQL queries can be traced without the USDT support using the -x option.

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) or PostgreSQL server with USDT probe support (when configuring the build: --enable-dtrace).

## OPTIONS

\-h Print usage message.

- \-p PID

  Trace this PID. If no PID is specified, the tool will attempt to automatically detect the MySQL or PostgreSQL processes running on the system.

- \-x PATH

  Path to MySQL binary. This option allow to MySQL queries even when USDT probes aren't enabled on the MySQL server.

- \-m THRESHOLD

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

- {mysql,postgres}

  The database engine to trace.

## EXAMPLES

- Trace MySQL server queries slower than 1 ms:

  \# **dbslower mysql**

- Trace slower than 10 ms for PostgreSQL in process 408:

  \# **dbslower postgres -p 408 -m 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 256 characters.

## OVERHEAD

This adds low-overhead instrumentation to 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

Sasha Goldshtein, Brendan Gregg

## SEE ALSO

biosnoop(8), mysqld\_qslower(8), dbstat(8)