---
title: "What else runs on your Postgres server, and how do we stop it from taking the database down?"
description: "The Postgres VM described here runs PgBouncer instances, a backup agent, metrics exporters, a local Prometheus, a log collector, and watchdog timers alongside the database. Those processes share machine-wide resources outside Postgres’s huge-page-backed shared_buffers, so leaks, CPU saturation, or disk exhaustion can threaten database availability. ClickHouse Managed Postgres places supporting services in a cgroup v2 slice and combines Go runtime GOMEMLIMIT targets with systemd memory.high and memory.max enforcement. GOMEMLIMIT encourages earlier garbage collection, memory.high applies reclaim and throttling, and memory.max provides a hard ceiling whose OOM scope excludes Postgres because it uses a separate cgroup. CPU weights, bounded buffers, log and metric controls, disk thresholds, and exemptions for replication and monitoring sessions extend isolation across other failure modes; these controls are enabled by default."
---

# What else runs on your Postgres server, and how do we stop it from taking the database down?

[Clickhouse](https://yomu.fyi/company/clickhouse) · Aug 21, 2026

**Type:** Problem & solution

## Summary

The Postgres VM described here runs PgBouncer instances, a backup agent, metrics exporters, a local Prometheus, a log collector, and watchdog timers alongside the database. Those processes share machine-wide resources outside Postgres’s huge-page-backed shared\_buffers, so leaks, CPU saturation, or disk exhaustion can threaten database availability. ClickHouse Managed Postgres places supporting services in a cgroup v2 slice and combines Go runtime GOMEMLIMIT targets with systemd memory.high and memory.max enforcement. GOMEMLIMIT encourages earlier garbage collection, memory.high applies reclaim and throttling, and memory.max provides a hard ceiling whose OOM scope excludes Postgres because it uses a separate cgroup. CPU weights, bounded buffers, log and metric controls, disk thresholds, and exemptions for replication and monitoring sessions extend isolation across other failure modes; these controls are enabled by default.

## Context

The Postgres VM runs multiple supporting processes alongside the database, including connection poolers, backup and monitoring agents, exporters, logging, and watchdogs. These processes share machine-wide memory, CPU, and disk resources with Postgres, so a memory leak, CPU-intensive backup, unbounded metrics cardinality, log burst, or full disk can cause a database availability incident.

## Approach / What changed

Supporting services are placed in a cgroup v2 slice with memory.high and memory.max limits, while Go services receive GOMEMLIMIT targets. Additional controls include lower CPU weight for backups, fixed WAL-G buffers, a log collector memory limiter, an allowlist for exported metrics, disk thresholds, and a watchdog that terminates ordinary application sessions at the emergency disk threshold while exempting replication and monitoring users. Postgres runs in a separate cgroup from supporting services.

## Takeaways

- GOMEMLIMIT gives Go services a runtime-level memory target, while memory.high triggers reclaim and throttling and memory.max supplies kernel-enforced cgroup OOM isolation.
- Backup CPU weight is reduced and WAL-G buffers are fixed as a fraction of RAM, limiting backup pressure on foreground database work and bounding memory as workload grows.
- At the disk emergency threshold, the watchdog terminates ordinary application sessions but preserves replication and monitoring sessions so WAL streaming and operational visibility remain available.

**Tags:** [Monitoring](https://yomu.fyi/topic/monitoring), [Observability](https://yomu.fyi/topic/observability), [Performance](https://yomu.fyi/topic/performance), [Postgres](https://yomu.fyi/topic/postgres), [Reliability](https://yomu.fyi/topic/reliability)

- Source: [Clickhouse](https://clickhouse.com/blog/protect-postgres-from-supporting-processes)
- Source URL: https://clickhouse.com/blog/protect-postgres-from-supporting-processes
- Ingested by Yomu: 2026-08-29T07:46:52.567Z

[Read original post](https://clickhouse.com/blog/protect-postgres-from-supporting-processes)