You can use the log files to troubleshoot issues with the
application placement controller, such as the placement of new instances.
apc.log file
The
application placement controller logs information regarding application
placement decisions the
apc.log file. You can
submit this file when you contact IBM® support
so that decisions that are made by the application placement controller
can be understood.
You can enable the application placement controller
logs with the apc.log.enablePlacementLog custom property. To change
the size and number of log files, edit the apc.log.LogFileSize and
apc.log.numHistoricalFiles custom properties.
SystemOut.log file
You
can look for
DCPC400 messages in the
SystemOut.log file
of the node that runs the application placement controller. These
messages contain information regarding the input and result of a placement
cycle. This information can be useful in understanding the decisions
made by the placement controller. For example:
[7/23/08 10:42:12:086 EDT] 0000006f APCXDMapHelpe I DCPC400I: Application Placement Controller Input is
Cluster name is dc1:
Cluster's properties: Type=DYNAMIC, Operational Mode=AUTOMATIC, Minimum Instances=2, Maximum Instances=2,
Isolation Preference=None, Vertical Stacking Number=Disabled, Lazy Start Time=Disabled,
Idle Stop Time=Disabled, Current Memory Size=371.2 MB, Maximum Heap Size=256.0 MB
Cluster's Demands: CPU Demand=0.0, Memory Demand=0.0
Cluster's Utility: {UtilityFunctionLinear extantDemand=0.0, utility=1.0}
Cluster's Node Membership: jpcammar01Cell01/elara11Node01, jpcammar01Cell01/elara11Node02,
Cluster's Members: jpcammar01Cell01/elara11Node01/dc1_elara11Node01,
jpcammar01Cell01/elara11Node02/dc1_elara11Node02,
Cluster's Placements: None
[7/23/08 10:42:12:090 EDT] 0000006f APCXDMapHelpe I DCPC400I: Application Placement Controller Output is
Cluster name is dc1:
Cluster's properties: Type=DYNAMIC, Operational Mode=AUTOMATIC, Minimum Instances=2, Maximum Instances=2,
Isolation Preference=None, Vertical Stacking Number=Disabled, Lazy Start Time=Disabled,
Idle Stop Time=Disabled, Current Memory Size=371.2 MB, Maximum Heap Size=256.0 MB
Cluster's Demands: CPU Demand=0.0, Memory Demand=0.0
Cluster's Utility: {UtilityFunctionLinear extantDemand=0.0, utility=1.0}
Cluster's Node Membership: jpcammar01Cell01/elara11Node01, jpcammar01Cell01/elara11Node02,
Cluster's Members: jpcammar01Cell01/elara11Node01/dc1_elara11Node01,
jpcammar01Cell01/elara11Node02/dc1_elara11Node02,
Cluster's Placements: elara11Node02/dc1_elara11Node02, elara11Node01/dc1_elara11Node01,
If
you look at the first
DCPC400 message, you can see
important information about the clusters:
- Cluster's properties: Displays cluster configuration information.
- Cluster's Demands: Displays the cluster demands on processor
and memory.
- Cluster's Utility: Displays the cluster capacity calculation.
- Cluster's Node Membership: Displays the nodes on which
a cluster member can reside.
- Cluster's Members: Displays the members of the cluster.
- Cluster's Placements: Displays the current placements of
the cluster.
By comparing the first
DCPC400 message,
which is the application placement controller input, to the second
DCPC400 message,
which is the application placement controller output, you can determine
that the application placement controller started instances of the
dc1 dynamic cluster on the elara11Node02 node and the elara11Node01
node. This conclusion was determined from the following data:
- From the Cluster's properties value in the first message,
the minimum and maximum number of cluster instances is set to 2.
- From the Cluster's Placements value on the first message,
you can conclude that no instances are running. Because no instances
are running, a breach of the minimum and maximum number of cluster
instances has occurred. As a result, two instances are started.
- From the Cluster's Placements value on the second message,
you can see that two instances were started: one instance on the elara11Node1
node and one instance on the elara11Node2 node. The instance names
are in the format of node_name/server_name.