Apache Cassandra Monitoring
及时发现 compaction 积压的 Cassandra 监控。
Obsfly 抓取 JMX MBean、compaction 统计、hints 队列大小与 repair 状态,翻译为每节点可执行的预测带。
Why monitor Cassandra
Cassandra's pathologies are unique: hot partitions, compaction storms, repair backlogs, and DC-to-DC latency tail. Generic DBM tools miss the JMX surface that exposes them.
What we scrape
Obsfly reads Cassandra through the surfaces operators already know. No driver changes, no extensions installed by us, no agent on the database itself.
JMX MBeans (org.apache.cassandra.metrics)
Read/Write latency histograms per keyspace and table.
JMX (org.apache.cassandra.db)
Compaction state, hint queue, dropped messages.
JMX (org.apache.cassandra.net)
Cross-DC and cross-node messaging metrics.
Slow query log (5.0+)
Per-CQL slow execution log with attribution.
system.* tables
system.peers, system.local for topology, hints state.
Key metrics tracked
Common Cassandra pains, and how Obsfly surfaces each
Compaction backlog growing under write load
Sign
Pending compactions climbs; SSTable count per partition grows.
Fix
Increase concurrent_compactors, tune compaction_throughput_mb_per_sec. Consider switching from STCS to LCS for read-heavy tables.
Hot partition detected
Sign
Latency tail dominated by one or two partitions; read repair rate spikes.
Fix
Schema problem. Re-shard the partition key to spread load.
Cross-DC tail latency
Sign
QUORUM/EACH_QUORUM consistency reads have long tails crossing DC boundaries.
Fix
Use LOCAL_QUORUM or LOCAL_ONE where consistency allows. Check DC link health via dropped messages.
vs Datadog DBM for Cassandra
Obsfly features for Cassandra
Feature
Query Summary
Top-N normalized queries with p50 / p95 / p99 latency, QPS, total time, rows touched, and plan-change history.
Feature
Anomaly Detection
ML-driven anomaly detection on every metric. Forecast bands, change-point detection, no thresholds to tune.
Feature
Configuration Tracking
Database parameter inventory, drift from baseline, recommended values, change history with attribution.
FAQ
Cassandra vs ScyllaDB — both supported?+
Yes. ScyllaDB exposes Cassandra-compatible JMX (or the modern HTTP REST API). The agent picks the best-available surface.
Versions?+
Apache Cassandra 3.11, 4.x, 5.0. DataStax Enterprise. ScyllaDB 5.x and 6.x.