Splice Machine Troubleshooting and Best Practices
This topic provides troubleshooting guidance for these issues that you may encounter with your Splice Machine database:
- Restarting Splice Machine after an HMaster Failure
- Increasing Parallelism for Spark Shuffles
- Force Compaction to Run Locally
Restarting Splice Machine After HMaster Failure
If you run Splice Machine without redundant HMasters, and you lose your HMaster, follow these steps to restart Splice Machine:
- Restart the HMaster node
- Restart every HRegion Server node
Increasing Parallelism for Spark Shuffles
You can adjust the minimum parallelism for Spark shuffles by adjusting the value of the
splice.olap.shuffle.partitions configuration option.
This option is similar to the
spark.sql.shuffle.partitions option, which configures the number of partitions to use when shuffling data for joins or aggregations; however, the
spark.sql.shuffle.partitions option is set to allow a lower number of partitions than is optimal for certain operations.
Specifically, increasing the number of shuffle partitions with the
splice.olap.shuffle.partitions option is useful when performing operations on small tables that generate large, intermediate datasets; additional, but smaller sized partitions allows us to operate with better parallelism.
The default value of
Force Compaction to Run on Local Region Server
Splice Machine attempts to run database compaction jobs on an executor that is co-located with the serving Region Server; if it cannot find a local executor after a period of time, Splice Machine uses whatever executor Spark executor it can get; to force use of a local executor, you can adjust the
splice.spark.dynamicAllocation.minExecutors configuration option.
To do so:
- Set the value of
splice.spark.dynamicAllocation.minExecutorsto the number of Region Servers in your cluster
- Set the value of
splice.spark.dynamicAllocation.maxExecutorsto twice that number. Adjust these setting in the
Java Config Optionssection of your HBase Master configuration.
The default option settings are:
For a cluster with 20 Region Servers, you would set these to: