eG Monitoring
 

Measures reported by Db2DPFDirectIOTest

This test monitors the I/O activity on the currently active logical partitions.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Direct_read_rate Indicates the total number of direct reads by the application per second. In other words, it is the number of read operations that do not use the buffer pool. Reads/Sec Direct reads are performed in units, the smallest being a 512-byte sector. They are used when:
  • Reading LONG VARCHAR columns
  • Reading LOB (large object) columns
  • Performing a backup

A high value over a period of time may be indicative of a performance bottleneck.
Direct_write_rate Indicates the total number of direct writes by the application per second. In other words, it is the number of write operations that do not use the buffer pool. Writes/Sec Direct writes are performed in units, the smallest being a 512-byte sector. They are used when:
  • Writing LONG VARCHAR columns
  • Writing LOB (large object) columns
  • Performing a restore
  • Performing a load

A high value over a period of time may be indicative of a performance bottleneck.
Buffer_pool_io_rate Indicates the rate at which the buffer pool I/O operations are being done in this logical partition. IOPS In conjunction with the hit ratio statistics, and the characteristics of the applications executing, the I/O load may require adjustment of BUFFPAGE, or applications may require further tuning.