test-protocol Plugin Spec

Overview

test-protocol is a plugin to test the following categories of APIs:

Net Processor API

• TSNetAccept

Protocol API

• TSNetVConnRemoteIPGet
• TSNetVConnRemotePortGet
• TSIOBufferSizedCreate
• TSIOBufferWaterMarkGet
• TSIOBufferWaterMarkSet
• TSIOBufferWrite

Logging API

• TSTextLogObjectCreate
• TSTextLogObjectHeaderSet
• TSTextLogObjectRollingEnabledSet
• TSTextLogObjectRollingIntervalSecSet
• TSTextLogObjectRollingOffsetHrSet
• TSTextLogObjectWrite
• TSTextLogObjectFlush
• TSTextLogObjectDestroy

It basically simulates the the server side in a client/server connection. We'll have a separate synthetic client which keeps sending requests to this server. The server receives the request, sends back the response to the client and logs the client's requests in a log file. During the process, it calls all the APIs listed above with different parameters and in different scenarios.

Feature Description

Client Description

Before the plugin features are described, we need to first specify what requests the synthetic client sends to the plugin and what responses it expects to get back from the plugin.

The client sends requests in the following format:

pattern number

pattern is a character string. number is the number of times the pattern is being repeated.

The plugin gets pattern and number, repeats the pattern in number of times and sends it back to the client.

The usage of the client is:

java ClientTest -P <proxy> -p <proxy_port> -a <pattern> -n <number> -l <loop>

<loop> is the number of requests the client sends to the proxy. If it's -1, the client will send requests in an infinite loop.

Plugin Description

The plugin will be configured in plugin.config as:

test_protocol.so <accept_port>

accept_port is the port that the plugin listens and accepts the client's requests.

The following are the steps the plugin performs:

1) Create a text log object

Create a text log object with TSTextLogObjectCreate, set its header with TSTextLogObjectHeaderSet, and set the rolling parameters with TSTextLogObjectRollingEnabledSet, TSTextLogObjectRollingIntervalSecSet and TSTextLogObjectRollingOffsetHrSet.

2) Listen for and accept client requests

It calls TSNetAccept to listen on a specific port and accepts the requests from the client. The handler function of the callback continuation for TSNetAccept checks if the connection has been established successfully (by checking if it's called back with the event TS_EVENT_NET_ACCEPT). The caller also checks the return value of TSNetAccept to see if it makes sense.

3) Get the remote IP and port of the net vconnection.

The callback function of TSNetAccept calls TSNetVConnRemoteIPGet and TSNetVConnRemotePortGet to get the remote IP and port of the net vconnection. It then schedules another continuation call to handle the following work.

4) Read the client request content into a buffer

Call TSVConnRead to read the client's request into an IOBuffer. Set the watermark of the client request IOBuffer with TSIOBufferWaterMarkSet. The IOBuffer calls back the continuation only when watermark amount of data is available. Use TSIOBufferWaterMarkGet to check if the watermark is set correctly.

5) Parse the client's request

Get the pattern and number from the client request and check if they exceed the length limits.

6) Log the client's request

Write the client request into the log with TSTextLogObjectWrite, flush the log with TSTextLogObjectFlush and destroy the log object with TSTextLogObjectDestroy.

7) Create the response being sent to the client

Repeat the pattern for number of times and saves it in a buffer. This will be the response sent back to the client.

8) Send the response to the client

Create an IOBuffer for client response with TSIOBufferSizedCreate, write the response to the IOBuffer with TSIOBufferWrite, then call TSVConnWrite to send the response to the client.

Plugin Structure