HDFS Canary
This is an HDFS service-level health test that checks that basic client operations are working and are completing in a reasonable amount of time. This test reports the results of a periodic "canary" test that performs the following sequence of operations. First, it creates a file. By default, the path is /tmp/.cloudera_health_monitoring_canary_timestamp. The canary test then writes a small amount of data to that file, reads that data back, and verifies that the data is correct. Lastly, the canary test removes the created file. The test returns "Bad" health if any of the basic operations fail. The test returns "Concerning" health if the canary test runs too slowly. A failure of this health test may indicate that the cluster is failing to satisfy basic client requests correctly or in a timely fashion. Check the status of the NameNode and other service-level health tests. Look in the Service Monitor logs for log messages from the canary test. Look in the NameNode logs for more details about the processing of the canary test requests. This test can be enabled or disabled using the HDFS Canary Health Check HDFS service-wide monitoring setting.
Short Name: HDFS Canary
HDFS Canary Health Check
- Description
- Enables the health check that a client can create, read, write, and delete files
- Template Name
- hdfs_canary_health_enabled
- Default Value
- true
- Unit(s)
- no unit