Provided by: bpfcc-tools_0.26.0+ds-1ubuntu2_all
NAME
dbstat - Collect histograms of MySQL/PostgreSQL query latencies.
SYNOPSIS
dbstat [-v] [-p PID [PID ...]] [-m THRESHOLD] [-u] [-i INTERVAL] {mysql,postgres}
DESCRIPTION
This traces queries served by a MySQL or PostgreSQL server, and collects a histogram of query latencies. The histogram is printed at the end of collection, or at specified intervals. 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. 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. -m THRESHOLD Minimum query latency (duration) to trace, in milliseconds. Default is all queries. -u Display query latencies in microseconds (default: milliseconds). -i INTERVAL Print summaries (histograms) at this interval, specified in seconds. {mysql,postgres} The database engine to trace.
EXAMPLES
Display histogram of MySQL query latencies: # dbstat mysql Display histogram of PostgreSQL query latencies slower than 10ms in pid 408: # dbstat postgres -p 408 -m 10 Display histogram of PostgreSQL query latencies at 3-second intervals: # dbstat postgres -i 3
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
SEE ALSO
dbslower(8)