SingleStore DB

7. Checking Partition Number and Data Skew

This step checks whether there are enough partitions and if data is properly balanced across your cluster.

  1. Check the total core to partition ratio per leaf for the database that is having trouble:

    • Run SHOW PARTITIONS on the database in question and compare that with the total number of cores in your cluster.

    • Is this ratio at least 1:1? If you have high concurrency, consider increasing the concurrency from 2, 3, or 4 to 1 core to partition ratio.

  2. Check that your data is balanced across the cluster properly by running EXPLAIN REBALANCE PARTITIONS on the database in question. If you see a non-empty set, run REBALANCE PARTITIONS on the database.

  3. Check that your data is redundant by running EXPLAIN RESTORE REDUNDANCY. If you see a non-empty set, run RESTORE REDUNDANCY

  4. Data Skew: see the Detecting and Resolving Data Skew.

Next Steps
  • If there are enough partitions, and no data skew is detected: move onto Step 8.