Performance Meters

PerformanceMeter is a collection of callbacks that the implementation could know when a request is sent, arrives or is is processed.

As shown above, T1-T5 identifies the following callbacks.

• T1: PerformanceMeter.requestStartAtClient (String, Execution, long)
• T2: PerformanceMeter.requestStartAtServer(String, Execution, long)
• T3: PerformanceMeter.requestCompleteAtServer(String, Execution, long)
• T4: PerformanceMeter.requestReceiveAtClient(String, Execution, long)
• T5: PerformanceMeter.requestCompleteAtClient(String, Execution, long)

Thus,

• Server Execution Time: T3 - T2
• Client Execution Time: T5 - T4
• Network Latency Time: (T4 - T3) + (T2 - T1)

How it works

Notice that, when we make a connection to load a page for the first time, only Server Execution Time is available. T4 and T5 will be saved on the client-side and sent back along with the next request.

If you print the request ID and the method name, when zk calls a performance monitor. You will see a different log between loading a zul and sending an AU request.

Request a ZUL

If load a zul 3 times:

# first load zul
requestId1st - requestStartAtServer
requestId1st - requestCompleteAtServer

# 2nd load zul
requestId1st - requestReceiveAtClient
requestId1st - requestCompleteAtClient
requestId2nd - requestStartAtServer
requestId2nd - requestCompleteAtServer

# 3rd load zul
requestId2nd - requestReceiveAtClient
requestId2nd - requestCompleteAtClient
requestId3rd - requestStartAtServer
requestId3rd - requestCompleteAtServer

Send AU Requests

If you send 2 AU requests, you will see a log like:

# 1st au
requestId - requestReceiveAtClient
requestId - requestCompleteAtClient
requestId-0 - requestStartAtClient
requestId-0 - requestStartAtServer
requestId-0 - requestCompleteAtServer

# 2nd au
requestId-0 - requestReceiveAtClient
requestId-0 - requestCompleteAtClient
requestId-1 - requestStartAtClient
requestId-1 - requestStartAtServer
requestId-1 - requestCompleteAtServer

• only when sending au request, zk calls requestStartAtClient()

Register as a Listener

Once implemented, you need to register it as a listener in WEB-INF/zk.xml to make it work: (assume the class is called foo.MyMeter):

    <listener>
        <listener-class>foo.MyMeter</listener-class>
    </listener>