Question-: In your Cassandra cluster you have a heavy write, then which of the compaction strategy most suitable? A. Size tiered compaction strategy B. Leveled compaction strategy C. Tombstone compaction strategy D. Expired data compaction strategy
Answer: A Exp: When your database has a heavy write then you should avoid using the leveled compaction strategy. Because using the leveled compaction strategy can create heavy IO. The best available option for this is size tiered compaction strategy. When you use size tiered compaction strategy with heavy write application of workloads then it delays the compaction as much as possible and over all IO can be reduced Because of compaction.
Question-: When you issue “nodetool compact� it will A. Initiate major compaction. B. Initiate minor compaction. C. Initiate Tombstone compaction D. Creates one large SSTable E. This would result in high IO
Answer: A, D,E
Explanation: Whenever user issues “nodetool compact� command, then Cassandra initiate major compaction. Which would try to create a single SSTable out of all the available SSTable, which is not a good idea, and this command should be avoided. While creating a single large SSTable, it would create lot of IO and affect overall system performance.
Question-: Size tiered compaction triggers compaction process based on the number of tables? A. True B. False
Answer: B Exp: size tiered compaction process is based on the number of SSTables and not on the number of tables in the Cassandra cluster or key space.