We’re happy to announce the beta release of Dynatrace Cassandra monitoring! Apache Cassandra server monitoring provides information about database exceptions, failed requests, performance, and more. You’ll know immediately if your Cassandra databases are underperforming. And when problems occur, it’s easy to see which nodes are affected.

To view Cassandra monitoring insights

  1. Click Technologies in the menu.
  2. Click the Cassandra tile.
    Note: Monitoring of multiple Cassandra clusters isn’t supported in this beta release.
  3. To view cluster metrics, expand the Details section of the Cassandra process group.
  4. Click the Process group details button. 
    Cassandra monitoring
  5. On the Process group details page, select the Technology-specific metrics tab, where you can identify problematic nodes.
  6. Select a relevant time interval from the Time frame selector in the top menu bar.
  7. Select a metric type from the metric drop list beneath the timeline to compare the values of all nodes in a sortable table view.
  8. To access node-specific metrics, select a node from the Process list at the bottom of the page.
    Cassandra monitoring
  9. Click the Cassandra metrics tab. 
    Cassandra monitoringHere you’ll find valuable Cassandra node-specific metrics. The Exceptions and Failed requests charts show you if there’s a problem with the node. Pay particular attention to Unavailable Read/Write/RangeSlice counts. Increased latency while the number of operations remains stable typically indicates a performance issue.

Cassandra node metrics

Metric Chart Description
Exception count Exceptions Number of internal Cassandra exceptions detected. Under normal conditions, this metric should be zero.
Unavailable – Read Failed requests Number of Unavailable – Read exceptions encountered
Unavailable – Write Failed requests Number of Unavailable – Write exceptions encountered
Failed requests Number of Unavailable – RangeSlice exceptions encountered
Timeout – Read Failed requests Number of Timeout – Read exceptions encountered
Timeout – Write Failed requests Number of Timeout – Write exceptions encountered
Timeout – RangeSlice Failed requests Number of Timeout – RangeSlice exceptions encountered
Failure – Read Failed requests Number of read failure  exceptions encountered
Failure – Write Failed requests Number of Failure – Read exceptions encountered
Failure – RangeSlice Failed requests Number of Failure – RangeSlice exceptions encountered
Read Operation count Adverage number or Reads per second
Write Operation count Adverage number or Writes per second
RangeSlice Operation count Adverage number or RageSlices per second
Read Latency 95th percentile Average 95th percentile of transaction read latency
Write Latency 95th percentile Average 95th percentile of transaction write latency
RangeSlice Latency 95th percentile Average 95th percentile of transaction RangeSlice latency

Additional Cassandra node monitoring metrics

More Cassandra monitoring metrics are available on individual Process pages. Select the Further details tab to view these metrics.

Cassandra monitoring

Here you’ll find six tabs and plenty of informative metrics.

Cassandra monitoring

The Cache tab tells you about the Row cache and Key cache hit rates. The Disk usage tab provides essential understanding of the health of the Cassandra compaction process. On the Load tab you’ll find details about ongoing and past operations. Above-average Maximum latency measurements may indicate that you have some very slow requests. Charts on the Thread Pools tab should be empty, or at least be very low. A continuously high number of pending reads indicates a problem. For full details, see Pending task metrics for reads.

Additional Cassandra metrics

Metric Chart Description
Disk space Total disk space used  Total disk space used by SSTables, including obsolete tables waiting to be GC’d
Row cache hit rate Hit rate 2m row cache hit rate
Key cache hit rate Hit rate 2m key cache row hit rate
Load Storage load Size, in bytes, of the on-disk data the node manages
Bytes compacted Bytes compacted Total number of bytes compacted since server start
Pending tasks Compaction tasks pending Estimated number of compactions remaining to perform
Completed tasks Compaction tasks completed Number of completed compactions since server start
SSTable count SSTable count Number of SSTables on disk for this table
Hints Hints Number of hint messages written to this node since start. Includes one entry for each host to be hinted per hint
Average Read latency Average 95th percentile of transaction read latency
Maximum Read latency Max 95th percentile of transaction read latency
Average Write latency Average 95th percentile of transaction write latency
Maximum Write latency Max 95th percentile of transaction write latency
Average RangeSlice latency Average 95th percentile of transaction RangeSlice latency
Maximum RangeSlice latency Max 95th percentile of transaction RangeSlice latency
Average Read throughput Adverage number of reads per second
Maximum Read throughput Max number of reads per second
Average Write throughput Average number of writes per second
Maximum Write throughput Max number of writes per second
Average RangeSlice throughput Average number of RangeSlices per second
Maximum RangeSlice throughput Max number of RangeSlices per second
Mutation pending tasks Mutation pending tasks Number of queued mutation tasks
Read pending tasks Mutation pending tasks Number of read mutation tasks
ReadRepair pending tasks ReadRepair pending tasks Number of ReadRepair mutation tasks

Prerequisites

  • Cassandra 2.xx
  • Linux or Windows OS

Enable Cassandra monitoring globally

With Cassandra monitoring enabled globally, Dynatrace automatically collects Cassandra metrics whenever a new host running Cassandra is detected in your environment.

  1. Go to Settings > Monitoring > Monitored technologies.
  2. Set the Cassandra JMX switch to On.

Want to learn more?

Visit our dedicated webpage about Cassandra monitoring to read more about how Dynatrace supports Apache Cassandra.

Have feedback?

Your feedback about Dynatrace Cassandra monitoring is most welcome! Let us know what you think of the new Cassandra plugin by adding a comment below. Or post your questions and feedback to Dynatrace Answers.