Solr is a complex software product that tries to “degrade gracefully” when it is overloaded or is running out of resources. This can result in high CPU readings, high memory usage and high system load. This shows up as false-positive heartbeat alerts and 5xx connection timeouts, among other symptoms. If your system exhibits chronic problems, an upgrade to a larger deployment may be beneficial.
The graphs below show a real-life scenario where we upgraded a struggling NDC4 (2 cpu/4 GB ram/32GB disk) system to an NDC16 (4 cpu/16GB ram/128GB disk) system. The upgrade occurred at about 6 p.m. on the graphs.
The increase in CPU capacity had a visible impact, resulting in fewer heartbeat alerts.
System load dropped to manageable levels.
Before the upgrade, the system suffered from a severe memory limitation.
After the upgrade, connection errors just vanished.
How to Upgrade
To upgrade your deployment to a larger system, please see Can I upgrade up to a larger Solr deployment?
Questions?
Do not hesitate to contact the SearchStax Support Desk.