Outbound Queue Volume Example Calculation

Provides an example for calculating the outbound queue size.

Calculate the OutboundQueueVolume for tables T1, T2, and T3. Because selectivity is measured on a table basis (rather than a database basis), you must calculate outbound queue size for each table replicated through it. The formula is:
OutboundQueueVolume = sum(OutboundTableVolume * ReplicationSelectivity) + OutboundTransactionVolume
where:
  • OutboundTableVolume is taken from the calculations performed in Calculating Table Volume topic.

  • ReplicationSelectivity values are from the Site parameters.

  • TransactionVolume is the size of the Message begin and Message commit pairs (250 bytes + 200 bytes) times the TransactionRate.

The formula for calculating the OutboundQueueVolume for Site 1 (S1) is:
OutboundQueueVolumeS1 = OutboundTransactionVolume + (TableVolumeT1*ReplicationSelectivityT1,S1) + (TableVolumeT2*ReplicationSelectivityT2,S1) + (TableVolumeT3*ReplicationSelectivityT3,S1)
The OutboundQueueVolumes for the three sites are:
Site1 = (450*5) + (10K/sec*0.1) + (8K/sec*0.4) + (5K/sec*0.2) = 7K/sec
Site2 = (450*10) + (10K/sec*0.4) + (8K/sec*0.8) + (5K/sec*0) = 15K/sec
Site3 = (450*8) + (10K/sec*0.4) + (8K/sec*0) + (5K/sec*0.2) = 9K/sec