Case Studies

Problem: A customer running Patroni-managed PostgreSQL v15.17 (Patroni 3.3.2) asked whether Commvault backups can be taken from the DR site’s Standby Leader. The DR cluster is a replicating standby of Production. The request asked specifically whether WAL file generation can be started on the DR Standby Leader and whether Commvault’s option to delete WALs after […]

Problem: On a primary Sonatype Nexus instance running version 3.29.2-02, container images stored in Docker repositories were disappearing without any recorded user DELETE calls. The operator reported unexpected removals, noted release notes referencing a prior cleanup-policy UI bug (where day values were misinterpreted as seconds), and observed that repository artifacts had been cleaned automatically. The […]

Problem: A Patroni-managed PostgreSQL cluster (PostgreSQL 15.17, Patroni 3.3.2) running asynchronous replication intermittently failed to rejoin an ex-master after a physical host reboot performed as part of high‑availability testing. Test pattern: hard shutdown of the former primary for ~5 minutes, then restart. Symptom observed on restart: the node failed to rejoin with the error “requested […]

Problem: Argo CD UI responsiveness and application sync/refresh operations experienced frequent slowness and timeouts on a bare‑metal OpenShift cluster. Symptoms included UI timeout and long sync times when running bulk refresh/sync operations against an app‑of‑apps topology: sync jobs that exceeded a 1,800s pipeline timeout would fail. The environment manages ~5,200 Argo CD applications on a […]

Problem: An official Apache NiFi Docker image (standard distribution) was scanned by a security tool and reported a high-severity finding: sonatype-2024-3350 (commons-collections version 3.2.2). The scanner identified the vulnerable class (SetUniqueList) inside the nifi-toolkit-assembly artifact (zip:bin, NiFi distribution version 2.8.0). The deployment context was a stock NiFi image pulled from the vendor registry — no […]

Problem: Seven identical Patroni-managed PostgreSQL 15.15 clusters (Patroni 3.3.2) showed divergent behaviour for the same SELECT query: clusters labelled Cust 1–5 returned results quickly while Cust 6–7 returned the same query much slower. Dataset sizes, indexes, constraints and foreign keys were reported as equivalent across clusters. One temporary mitigation (set enable_mergejoin = false) had been […]

Problem: Client requested a step‑by‑step procedure to add two new servers to an existing three‑node Kafka cluster running in KRaft mode, with the explicit requirement to avoid any data loss. The cluster’s existing configuration (server.properties) and current controller.quorum.voters format were provided for reference. The observable concern was that adding voters and brokers incorrectly could cause […]

Problem: The data mount was approaching full capacity. Investigation showed that the keyspace-level backups directories inside the Cassandra data directories were consuming the majority of space (≈150 GB). No active snapshots were present on the cluster when the issue was reported. The cluster configuration had incremental_backups: true in cassandra.yaml because the customer wanted to retain […]

Problem: A Patroni-managed PostgreSQL cluster (PostgreSQL 15.8, Patroni 2.1.4) was reporting sustained high memory consumption on a host with ~275 GB of physical RAM and only ~8% free. The environment had HugePages enabled at the OS level. Patroni configuration showed shared_buffers=68GB, work_mem=20MB, max_parallel_workers_per_gather=4 and max_connections=2000. Observed behavior included consistently ~90% system memory utilization across a […]