As PostgreSQL continues to grow as a preferred open-source relational database for enterprise-grade applications, the need for consistent and detailed performance monitoring has never been more essential. Understanding how a PostgreSQL instance behaves over time enables administrators to proactively address performance bottlenecks, storage inefficiencies, and configuration issues before they become critical. While there are many solutions for real-time database monitoring, pgCluu offers a unique and effective way to capture detailed metrics in an offline, portable format.
This guide walks through installing and using pgCluu to generate comprehensive performance reports for PostgreSQL. It includes the installation process from source, data collection methods, and the types of insights provided by the tool. The guide also explains why these reports are essential for database administrators (DBAs), especially when conducting audits, preparing for capacity upgrades, or debugging performance anomalies.
What is pgCluu?
pgCluu stands for PostgreSQL Cluster Log and Utilization tool. It is a two-part performance monitoring utility that collects and analyzes data from PostgreSQL instances and their host operating systems. Unlike live dashboard-based tools that require persistent server access and background services, pgCluu operates in two distinct stages:
- pgcluu_collectd: A lightweight Perl script that collects performance and activity metrics over time.
- pgcluu: A report generator that compiles the collected metrics into a detailed, static HTML report with graphs and summaries.
The primary strength of pgCluu lies in its ability to work in offline and secure environments. It produces self-contained reports that can be archived, shared, or reviewed independently without live server connections or additional software.
Why Use pgCluu?
PostgreSQL offers many dynamic views and statistics, but correlating and visualizing them for long-term analysis can be tedious. pgCluu simplifies this by automating the collection and representation of critical PostgreSQL and system metrics. This makes it especially useful for:
- Diagnosing performance issues
- Conducting security or compliance audits
- Planning hardware upgrades
- Monitoring trends over weeks or months
- Analyzing usage in restricted environments (air-gapped networks)
Moreover, pgCluu is open source, scriptable, and relatively lightweight, making it ideal for inclusion in automated health check and maintenance routines.
Key Metrics and Visualizations Provided by pgCluu
The HTML report generated by pgCluu offers an extensive breakdown of PostgreSQL internals and host system activity, including:
System-Level Statistics:
- CPU Usage: Visualizes user, system, idle, and I/O wait time.
- Memory Usage: Shows available, cached, and free memory.
- Disk I/O: Displays read/write throughput and latency.
- Network Activity: Measures incoming/outgoing packets and bandwidth.
PostgreSQL Cluster Statistics:
- Active Connections: Graphs number of sessions and concurrent users.
- Transaction Rates: Shows transactions per second (TPS) over time.
- Checkpoints: Includes checkpoint frequency, duration, and write rates.
- Locks: Details about lock types, wait events, and contention.
- Autovacuum Activity: Tracks vacuum runs and table cleaning statistics.
Database and Table-Level Insights:
- Database Sizes: Growth trends for individual databases.
- Index Usage: Number of index scans vs. sequential scans.
- Table Bloat: Identifies space wastage in tables and indexes.
- Top Queries: Longest-running queries and execution patterns.
WAL and Replication:
- WAL Usage: Amount of write-ahead log data generated.
- Replication Statistics: Lag, write/sync/apply rates per standby.
This information empowers DBAs to assess workload characteristics, isolate inefficiencies, and validate tuning changes with measurable data.
Installing pgCluu from Source on Ubuntu
Step 1: Install Required Packages
Install dependencies, including required Perl modules and charting utilities.
sudo apt-get update
sudo apt-get install make gcc libdbi-perl libdbd-pg-perl libtime-hires-perl \
libjson-xs-perl libtext-csv-perl libcgi-fast-perl \
libhtml-template-perl libio-compress-perl gnuplot
These dependencies cover PostgreSQL metric access, system information parsing, and report generation.
Step 2: Clone the Git Repository
git clone https://github.com/darold/pgcluu.git
cd pgcluu
This pulls the latest source code from the official GitHub repository.
Step 3: Build and Install
sudo perl Makefile.PL
sudo make && sudo make install
This step builds and installs the binaries to /usr/local/bin. If symbolic link warnings appear, they are typically harmless unless installation fails completely.
Step 4: Confirm Installation
pgcluu --version
pgcluu_collectd --help
If version information displays correctly, you’re ready to begin data collection.
How to Generate a pgCluu Performance Report
Step 1: Collect Statistics with pgcluu_collectd
Choose a directory to store the raw data and start collecting statistics:
mkdir -p /var/tmp/pgcluu_data
sudo PGPASSWORD=<your_password> pgcluu_collectd -i 10 /var/tmp/pgcluu_data -U postgres -h localhost -p 5432
- -i 10 sets a 10-second interval between samples.
- Adjust the duration of collection based on how much data you want.
This command runs continuously. Stop it using Ctrl + C after the desired period.
Step 2: Generate the HTML Report
After data collection:
pgcluu -o /var/tmp/pgcluu_report /var/tmp/pgcluu_data
This creates a full report in the specified output directory. To view it:
xdg-open /var/tmp/pgcluu_report/index.html
If permission issues arise, ensure ownership and permissions are correctly set:
sudo chown -R $USER:$USER /var/tmp/pgcluu_report
Limitations to Consider
- pgCluu is not a real-time monitoring tool.
- It does not offer alerting or auto-remediation.
- Large data collection over days may consume significant disk space.
Despite these, for snapshot-based reporting and historical analysis, it excels with minimal setup and zero runtime interference.
Conclusion
pgCluu stands out as an indispensable tool for PostgreSQL database administrators who seek clarity, accountability, and actionable insights. Its ability to create in-depth, visual reports from system and database metrics makes it highly suitable for organizations that value transparency in performance monitoring without depending on persistent background services or live dashboards.
Whether you're managing production workloads, conducting audits, preparing for growth, or working within restricted environments, pgCluu offers a highly flexible and efficient reporting solution. By capturing the state of your PostgreSQL cluster in a detailed and readable format, it helps you stay informed and in control of your database health and performance.
Adopting pgCluu into your toolkit means adopting better visibility, faster problem resolution, and proactive infrastructure planning.