hydra

Class HydraThreadGroup

java.lang.Object

hydra.HydraThreadGroup

All Implemented Interfaces:

Serializable

public class HydraThreadGroup
extends Object
implements Serializable

A hydra thread group is used to carve out a fixed subset of the available client thread pool for a task or set of tasks to use. Each thread belongs to exactly one thread group.

A hydra thread group is specified by a logical name and a list of HydraThreadSubgroup, each of which contains the total number of threads in the subgroup, an optional number of VMs from which to choose the threads, and an optional set of logical client names from which to choose the VMs.

Threads not otherwise assigned to groups are assigned to the default group, named DEFAULT_NAME.

INITTASKs, CLOSETASKs, and TASKs can optionally specify a list of thread groups where they will be scheduled to run. INITTASKs and CLOSETASKs that do not specify any thread groups are scheduled on all thread groups. TASKs that do not specify any thread groups are scheduled on the default thread group only. Thread groups not specified by any INITTASK, CLOSETASK, or TASK are ignored and not mapped to any threads.

Tasks using the same thread group can run concurrently with themselves and each other, unless the global parameter Prms.serialExecution is true. They are also typically be scheduled onto different client threads from one execution to the next. The timing, relative priority, and termination characteristics of tasks within the thread group are handled separately using per-task and test-wide attributes.

Thread Subgroup Parameters:

-- totalThreads (int) The total number of threads in one subgroup of the thread group.

-- totalVMs (int) (optional) The "totalThreads" threads for this thread subgroup are scattered as evenly as possible across the specified number of VMs. Omit this to allow the scheduler to use any number of VMs.

-- clientNames (comma-separated list of strings) (optional) The VMs used for this thread subgroup are chosen from VMs with the corresponding logical client name. Omit this to allow the scheduler to use any logical client types.

Sample usage scenarios:

-- To allow a set of tasks to compete for 5 fixed threads, set totalThreads=5 and assign those tasks to the thread group.

-- To run a given task exclusively in 1 thread in 5 VMs, set totalThreads=5 totalVMs=5 and assign only that task to the thread group.

-- To run Task A exclusively on 2 single-threaded VMs, Task B and Task C on 4 VMs with 25 threads each, and Task D exclusively on 1 thread in each of those same 4 VMs, define: hydra.ClientPrms-clientNames single multi; hydra.ClientPrms-vmQuantities 2 4; hydra.ClientPrms-vmThreads 1 26; THREADGROUP ForTaskA totalThreads=2 totalVMs=2 clientNames=single; THREADGROUP ForTaskBC totalThreads=100 totalVMs=4 clientNames=multi; THREADGROUP ForTaskD totalThreads=4 totalVMs=4 clientNames=multi; Then assign each task to the appropriate thread group.

-- To include an exclusive thread running Task D on Task A's VMs, define: hydra.ClientPrms-clientNames single multi; hydra.ClientPrms-vmQuantities 2 4; hydra.ClientPrms-vmThreads 2 26; THREADGROUP ForTaskA totalThreads=2 totalVMs=2 clientNames=single; THREADGROUP ForTaskBC totalThreads=100 totalVMs=4 clientNames=multi; THREADGROUP ForTaskD totalThreads=6 totalVMs=6 clientNames=single,multi; Then assign each task to the appropriate thread group.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_NAME Name of the default thread group

Constructor Summary

Constructors

Constructor and Description
HydraThreadGroup(String s) Create a hydra thread group with the given name.

Method Summary

Modifier and Type	Method and Description
void	addSubgroup(HydraThreadSubgroup subgroup) Adds a subgroup to this thread group.
String	getName() Gets the name of this thread group.
HydraThreadSubgroup	getSubgroup(int i) Gets the i'th subgroup that makes up this thread group.
Vector	getSubgroups() Gets the subgroups that make up this thread group.
int	getTotalThreads() Gets the total number of threads in this thread group (lazily).
SortedMap	toSortedMap()
String	toString()
Boolean	usesCustomWeights() Gets whether the tasks that use this thread group use custom weights.
void	usesCustomWeights(Boolean b) Sets whether the tasks that use this thread group use custom weights.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_NAME

public static final String DEFAULT_NAME

Name of the default thread group

See Also:

Constant Field Values

Constructor Detail

HydraThreadGroup

public HydraThreadGroup(String s)

Create a hydra thread group with the given name.

Method Detail

getName

public String getName()

Gets the name of this thread group.

usesCustomWeights

public Boolean usesCustomWeights()

Gets whether the tasks that use this thread group use custom weights.

usesCustomWeights

public void usesCustomWeights(Boolean b)

Sets whether the tasks that use this thread group use custom weights.

getSubgroups

public Vector getSubgroups()

Gets the subgroups that make up this thread group.

getSubgroup

public HydraThreadSubgroup getSubgroup(int i)

Gets the i'th subgroup that makes up this thread group.

addSubgroup

public void addSubgroup(HydraThreadSubgroup subgroup)

Adds a subgroup to this thread group.

getTotalThreads

public int getTotalThreads()

Gets the total number of threads in this thread group (lazily).

toSortedMap

public SortedMap toSortedMap()

toString

public String toString()

Overrides:

toString in class Object