pgCluu v4.0 released

Hyderabad, India - March 6, 2025

## pgCluu

**PostgreSQL Cluster Utilization**

pgCluu is a Perl program used to perform a full audit of a PostgreSQL
Cluster performances. It is divided in two parts, a collector used to
grab statistics on the PostgreSQL server using psql and sar, a reports
builder that will generate all HTML and charts output.

Version 4.0 of pgCluu have been released, this is a major release that
adds several new features and reports. It also fixes issues reported
since the last release.

New features:

* Add report of devices `/sys/block/queue` informations (scheduler,
rotational, rq_affinity and add_random) to the System report.
* Add report of PGDATA files to be able to detect symlinks and
unwanted files in this directory.
* Add reports for Wait Event when the `pg_wait_sampling` extension is use.
First report show the distribution by Wait Event Type and second report
show the distribution by Wait Events.
* Add report for Global subtransactions counters if extension
`pg_subxact_counters` is installed in the connection database.
Subtransactions can lead to performance issue, report Counters
to monitor the subtransactions (generation rate, overflow, state).
* Add collect of `/sys/kernel/debug/sched/migration_cost_ns` with kernel >= 5.19
collect start-end metrics only twice (start and end)
* Add a chapter in documentation about additional statistics
collected from extensions `pg_stat_statements`, `pg_wait_sampling`
and `pg_subxact_counters`.
* Add option `--no-pg_stats-dump` to pgcluu_collectd to avoid collecting such
statistics for performances reasons.
* Make SIGINT interrupts gracefully pgcluu_collectd like SIGHUP.
* Add dump of the pg_stats view to pgcluu_collectd. The point is for the
DBA to study the statistics, and nothing else.

Backward compatibility:

There is no backward compatibility issues but a change of behavior with default
to dump the pg_stats view. Following the number of table/indexes in the
databases it could take more time collecting the statistic so in this case
the interval of polling should be increase. There is an new option to disable
the pg_stats dump, `--no-pg_stats-dump`, if you want to get back to the previous
behavior.

See [ChangeLog](https://github.com/darold/pgcluu/releases/tag/v4.0) for
a complete list of changes, bug fixes and acknowlegements.

## About pgCluu:

The goal of this project is to provide a complete PostgreSQL auditing
tool that don't need any dependency to be run easily to audit a local
or remote server.

If you just have a sar output file, pgCluu can be use to draw graphs
about the system utilization only.

###Credits

pgCluu is an original collection of tools built during my work at
[Dalibo](https://www.dalibo.com) and [HexaCluster](https://hexacluster.ai/).
The tools are published under the PostgreSQL License.

pgCluu is created and maintained by Gilles Darold. Any contribution to
build a better tool is welcome. You can send your ideas, features requests
or patches using the GitHub tools.

###Links

View a sample report at [http://pgcluu.darold.net/example/index.html](http://pgcluu.darold.net/example/index.html)

* Web site: [http://pgcluu.darold.net/](http://pgcluu.darold.net/)
* Download: [https://github.com/darold/pgcluu/releases](https://github.com/darold/pgcluu/releases)
* Development: [https://github.com/darold/pgcluu](https://github.com/darold/pgcluu)
* Documentation: [https://github.com/darold/pgcluu/blob/master/README](https://github.com/darold/pgcluu/blob/master/README)