Application placement custom properties

Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS

Application placement custom properties

Custom properties modify the application placement controller configuration. You can use these settings to tune the application placement controller behavior beyond the settings that are in the administrative console.
apc.log.enablePlacementLog

You can use the apc.log.enablePlacementLog custom property to enable or disable logs from being saved to the apc.log log file. The apc.log log file contains information about placement decisions. IBM support can use this log file to help understand the placement decisions that are being made by the application placement controller. To define the custom property, perform the following steps:

In the administrative console, click Operational Policies > Autonomic managers > Application placement controller > Custom properties > New.
Type the name of the custom property: apc.log.enablePlacementLog
Specify the value as false to disable the log.
Click Apply and save your configuration.

apc.log.LogFileSize

You can use the apc.log.LogFileSize custom property to set the size of the application placement controller log file, the apc.log file, to a size in megabytes. The default size is 20 megabytes, but you can change the default value.
To set the custom property, perform the following steps:

In the administrative console, click Operational Policies > Autonomic managers > Application placement controller > Custom properties > New.
Type the name of the custom property: apc.log.LogFileSize
Specify the value as an integer value of the number of megabytes for the log file. For example, if you enter 100, the log file would be 100 megabytes.
Click Apply and save your configuration.

apc.log.numHistoricalFiles

You can use the apc.log.numHistoricalFiles custom property to set the number of log files that are saved for the application placement controller. When the application placement controller log file reaches its maximum size, the historical file is saved if this value is greater than 1. If the value is equal to 1, the historical data appends to the existing file.

In the administrative console, click Operational Policies > Autonomic managers > Application placement controller > Custom properties > New.
Type the name of the custom property: apc.log.numHistoricalFiles
Specify an integer value that specifies the number of historical files you want to save, for example, 2.
Click Apply and save your configuration.

cpuUtilizationThreshold custom property

You can use the cpuUtilizationThreshold custom property to define the percentage of processor power that you can use on each node in a cell.
The cpuUtilizationThreshold custom property defines the percentage of processor power that is used on the nodes in your environment. The default value is 100, which means that 100% of the processor can be used on each node in the cell. For configurations that involve z/OS^® nodes, set this value to less than 100.
The application placement controller attempts to compute placements so that the utilization of any node does not exceed the defined threshold. The application placement controller considers all processes, including processes that are not related to WebSphere^® Application Server or WebSphere Virtual Enterprise when making these calculations. Important: This property must be defined and must be set to a value less than 100 for configurations that involve z/OS nodes. You can set this property on the cell to apply to all the nodes in the cell or you can specify the value for a particular node in your configuration. To define the property to specify the threshold for all nodes in the cell, perform the following steps:

In the administrative console, click Operational policies > Autonomic managers > Application placement controller > Custom properties > New.
Type the name of the custom property as cpuUtilizationThreshold.
Specify the percentage of processor power to use on each node in the cell.
Click Apply and save your configuration.

GenerateUniquePorts custom property

You can use the GenerateUniquePorts custom property to generate unique ports for each dynamic cluster member. By default, dynamic cluster members on distributed nodes are created with unique ports, while z/OS nodes do not have unique ports. On the z/OS platform, port numbers are usually set symmetrically according to specific range of numbers. The first dynamic cluster member always has unique ports, and these port numbers are applied to the other dynamic cluster members. You can set this property on the node group or on an individual node.

Setting the custom property on the node group:

In the administrative console, click System administration > Node groups > node_group_name > Custom properties > New.
Type GenerateUniquePorts as the name of the custom property.
Specify the value as true or false. By specifying true, unique ports are generated for each dynamic cluster member. By specifying false, unique ports are created for the first dynamic cluster member, and subsequent dynamic cluster members use the same ports.

Setting the custom property on a node:

In the administrative console, click System administration > Node groups > node_group_name > Custom properties > New.
Type GenerateUniquePorts.node_name as the name of the custom property, where the node_name variable is the name of the node in the node group.
Specify the value as true or false. By specifying true, unique ports are generated for each dynamic cluster member on the specified node. By specifying false, unique ports are created for the first dynamic cluster member on the node, and subsequent dynamic cluster members use the same ports.

Table 1. GenerateUniquePorts custom property default values

default (z/OS) false Attention: If vertical stacking is enabled for a z/OS dynamic cluster, the port allocation strategy is forced to true, to generate unique ports for each dynamic cluster member.
default (distributed platforms) true

HttpSessionRebalanceOff custom property

You can use the HttpSessionRebalanceOff custom property to disable HTTP session rebalancing.
With WebSphere Extended Deployment V6.0 or later, HTTP session rebalancing is automatically enabled. You can use HTTP session rebalancing to reassign existing session affinities to new servers that become available for processing the given Web application. See HTTP session rebalancing for more information.
Use the HttpSessionRebalanceOff custom property if you want to return your configuration to the old HTTP session behavior, where session affinities are established with a particular application server and are not reassigned to any new servers that become available.
Session rebalancing is disabled by default on any dynamic clusters that consist of servers that are not running WebSphere Application Server, such as PHP or Tomcat servers, because you might have another session clustering mechanism deployed for those servers.
You might consider disabling HTTP session rebalancing if your session sizes are large. If your sessions are large, the cost of moving the sessions to a new server might be more than the benefit of taking the workload off of the original server. You can use Performance Monitoring Infrastructure (PMI) data to make the decision to turn off session rebalancing. You might see in your PMI data that response time, memory utilization, and processor utilization increases on specific servers to transfer the session information. See the WebSphere Application Server Network Deployment Information Center for more information about analyzing PMI data and best practices for using HTTP sessions.
If you leave session rebalancing on, as sessions become more evenly distributed, and memory and processor utilization also become more evenly distributed across the servers in the cluster. If a cluster is more balanced, it is easier for WebSphere Virtual Enterprise to make autonomic decisions.
Perform the following steps to disable HTTP session rebalancing:

In the administrative console, click Servers > Dynamic clusters > dynamic_cluster_name > Custom properties > New.
Type the name as HttpSessionRebalanceOff and set the value to true.
Click Apply and save your configuration.

To turn session rebalancing back onfor dynamic clusters that consist of WebSphere Application Server application servers, delete the custom property. To enable session rebalancing in dynamic clusters that consist of servers that are not WebSphere Application Server application servers, such as PHP or Tomcat servers, perform the following steps:

In the administrative console, click Servers > Dynamic clusters > dynamic_cluster_name > Custom properties > New.
Type the name as HttpSessionRebalanceOff and set the value to false.
Click Apply and save your configuration.

memoryProfiler.isDisabled custom property

You can use the memoryProfile.isDisabled custom property to disable the memory profiler.
Under the default operation, the application placement controller profiles dynamic clusters online to determine their memory usage. You can disable this default operation by setting the memoryProfiler.isDisabled custom property to true. When the memory profiler is disabled, the application placement controller assumes a default memory usage value. This memory usage value is computed as 64k + 1.2 maxHeapSize, where maxHeapSize is the maximum heap size setting in the server template of the dynamic cluster. Perform the following steps to disable the memory profiler:

In the administrative console, click Operational Policies > Autonomic Managers > Application Placement Controller > Custom Properties > New.
Type the name as memoryProfiler.isDisabled and set the value to true.
Click Apply and save your configuration.

numVerticalInstances custom property

Use this custom property to define the number of dynamic cluster instances on a node.
Use this custom property only if the nodes in your dynamic cluster are heterogeneous and vary in power. If the nodes in your dynamic cluster are homogenous, you can define the number of dynamic cluster instances one time in the administrative console.
See Configure vertical stacking for more information.
OverlappingCells custom property
You can use the OverlappingCells custom property when two WebSphere Virtual Enterprise cells share the same physical host. Configuring this property ensures that the application placement controller does not overuse resources on the shared host.
See Configure application placement for cells that share the same nodes for more information about how to set this custom property. Enter the custom property value in the following format:
user_name:password@dmgr_host:port.SOAP 
If you are connecting three or more cells, separate the custom property values for each cell with a comma.

user_name: Name of the user that can log into the other cell.
password: Specifies the password for that user. You can encode the password so that it does not display in plain text in the administrative console. To encode a password, use the encodePassword script.
dmgr_host: Name of the deployment manager host for the other cell.
port: Specifies the SOAP port that is associated with the deployment manager, for example, the SOAP_CONNECTOR_ADDRESS port.
proactiveIdleStop custom property

You can use the proactiveIdleStop custom property to stop dynamic cluster instances during periods of inactivity.
This custom property adds function to the If other dynamic clusters need resources, stop all instances of this cluster during periods of inactivity setting in the administrative console. With the administrative console setting, instances stop only if other clusters in the cell need the resources that are being used by the inactive instances. You also specify an amount of time to wait before stopping instances for the cluster. By setting this custom property, inactive instances stop even if the resources are not required elsewhere in the environment. The cluster instance goes idle in the amount of time that you specified in the administrative console setting.
You can set this custom property on all dynamic clusters by creating the custom property on the cell level. You can also create the custom property on a single dynamic cluster. If the property is set on both the cell and the dynamic cluster, the dynamic cluster setting is used.

Click Servers > Dynamic clusters > dynamic_cluster_name. Verify that the If other dynamic clusters need resources, stop all instances of this cluster during periods of inactivity option is selected for your dynamic cluster and that you have the Time to wait before stopping instances specified. If this option is not selected, then the custom property that you create is ignored.
Click Custom properties > New or System administration > Cell > Custom properties > New.
Type the name as proactiveIdleStop and set the value to true. By default, this custom property is disabled.
Click Apply and save your configuration.

reservedMemoryFixed and reservedMemoryPercent custom properties
You can use these custom properties to define how much memory on each node to reserve for processes that are not related to WebSphere Application Server or WebSphere Virtual Enterprise. When these properties are defined, the total memory on a node for processes that are not related to WebSphere Application Server or WebSphere Virtual Enterprise can be calculated using the following formula:
reservedMemoryFixed + reservedMemoryPercent * (totalNodeMemory - reservedMemoryFixed)
Property name Definition Default
reservedMemoryFixed A fixed amount of memory to reserve. 64 MB
reservedMemoryPercent A percentage of memory to reserve. 5%
You can define these custom properties across the entire cell to apply to all nodes in the cell, or on individual nodes. To define these custom properties for all nodes in the cell, perform the following steps:

In the administrative console, click Operational Policies > Autonomic Managers > Application Placement Controller > Custom Properties > New.
Type the name of the custom property, either reservedMemoryFixed or reservedMemoryPercent.
Specify the reserved memory value to apply to all nodes in the cell.
Click Apply and save your configuration.
To define the custom properties for a particular node in your cell, perform the following steps:

In the administrative console, click Operational Policies > Autonomic Managers > Application Placement Controller > Custom Properties > New.
Type the name of the custom property, either reservedMemoryFixed.node_name or reservedMemoryPercent.node_name, where node_name is the name of your node. For example, if your node is named node1, the names of your custom properties are reservedMemoryFixed.node1 and reservedMemoryPercent.node1.
Specify the reserved memory value to apply for the specified node.
Click Apply and save your configuration.
useNodeFreeMemory custom property

Use this custom property to define a replacement to the reservedMemory default custom property. This custom property uses the node free memory statistic, plus the memory calculated for any dynamic cluster instances that are already on the node, to calculate the memory available for launching additional dynamic cluster instances. To define the custom property for a particular node in your cell, perform the following steps:

In the administrative console, click Operational Policies > Autonomic Managers > Application Placement Controller > Custom Properties > New.
Type the name of the custom property as: useNodeFreeMemory.
Specify true as the value to apply to all nodes in the cell.
Click Apply and save your configuration.
Related tasks

Creating dynamic clusters
Configure dynamic application placement

default (z/OS)	false Attention: If vertical stacking is enabled for a z/OS dynamic cluster, the port allocation strategy is forced to true, to generate unique ports for each dynamic cluster member.
default (distributed platforms)	true

Property name	Definition	Default
reservedMemoryFixed	A fixed amount of memory to reserve.	64 MB
reservedMemoryPercent	A percentage of memory to reserve.	5%