Neoview Workload Management Services Guide (R2.3)

executing first. In this example, when 15 queries in SERVICE1 finish executing, WMS allows five
queries in SERVICE1 and then 10 queries in SERVICE2 to start executing:
Waiting QueriesExpected
Percentage Based
on Priority Weight
Percentage of All
Executing Queries
Executing QueriesTotal QueriesService Name
20–5=1556%70/130 = 54%65+5=7085SERVICE1
10–10=033%30/130 = 23%20+10=3030SERVICE2
1011%30/130 = 23%3040SERVICE3
Example 2: How Service Priorities and System Resource Thresholds Work
Consider another example where there are 30 incoming queries associated with the low-priority
SERVICE3. The system resources reach their limits when the twentieth query of SERVICE3 starts
executing. WMS puts the ten remaining queries into the waiting queue.
Memory Usage
(limit = 85%)
CPU Busy (Limit =
100%)
Waiting QueriesExecuting QueriesTotal QueriesService Name
86%90%000SERVICE1
86%90%000SERVICE2
86%90%102030SERVICE3
When the system resource limits are met, WMS puts additional incoming queries into the waiting
queue. For example, if 60 queries associated with the high-priority SERVICE1 and 30 queries
associated with the medium-priority SERVICE2 come in to the system, WMS puts all those
queries into the waiting queue:
Memory Usage
(limit = 85%)
CPU Busy (Limit =
100%)
Waiting QueriesExecuting QueriesTotal QueriesService Name
86%90%0+60=6000+60=60SERVICE1
86%90%0+30=3000+30=30SERVICE2
86%90%102030SERVICE3
As queries finish executing, WMS dynamically balances the waiting and executing queries and
moves some queries from the waiting queue to the executing state based on the expected
percentage of executing queries and the priority of the service. For example, suppose that 10
queries finish executing in SERVICE3:
Waiting QueriesExpected
Percentage Based
on Priority Weight
Percentage of All
Executing Queries
Executing QueriesTotal QueriesService Name
6056%0/10 = 0%060SERVICE1
3033%0/10 = 0%030SERVICE2
1011%10/10 = 100%20–10=1030–10=20SERVICE3
If the percentage of executing queries in a service is equal to or lower than the expected percentage,
WMS allows the queries in the waiting queue to start executing, starting with queries in the
high-priority SERVICE1 and ending with the queries in a lower priority service. For example,
when 10 low-priority SERVICE3 queries finish executing, WMS allows 50 high-priority SERVICE1
28 Configuring WMS