Recently, we were able to do some clustering related load testing on Apache
Axis2
web services engine focusing on state replication property. I
thought of sharing things we did in our tests which were carried out
using Apache
JMeter.
Apache
JMeter is a fully open source pure java tool designed for the purpose
of load testing and measuring performance of web applications. According
to the documentation, it can be used to test both static and dynamic
web resources such as files, Servlets, web services, Perl scripts, Java
Objects, Data Bases and Queries, FTP Servers etc. JMeter can
effectively use to simulate heavy loads on the above resource types and
analyze the overall performance under different load conditions such as
concurrent loads. It also provide various types of visualization
techniques to graphically analyze the results obtained from the load
tests.
Here are some advantages of using JMeter
- Open Source free tool developed by Apache Software Foundation
- Has an active community, good documentation, user manuals and plenty of resources which makes easy to learn, get start and running
- Can load test in variety of server types such as HTTP, FTP, SOAP, Database, LDAP, JMS, Mail servers etc.
- Support large-scale testing providing concurrency and ability to use various types of loads.
- Support for distributed stress testing using multiple systems
- API and plug-ins available for customization
- Provides variety of test results manipulation and visualization methods
Let's get into the details.
Setting up the Environment
- JDK 1.5 or later version is required for JMeter latest released
version 2.7. Get more details about tested JDK versions and compatible
operating systems from here. You can go through my previous post to get more details about setting up Sun JDK 1.6 in Linux environment.
- Download JMeter binaries or checkout and build JMeter source available at repositories.
Unpack the archive(zip or tgz) to a local folder. Let [jMeterHome] be
the unpacked directory. Run JMeter from the terminal as follows.
Figure 01. JMeter GUI
.
Setting up Apache Axis2 and deploy the service
Here we will be deploying sample service available in Apache Axis2 called StockQuoteService which provides two method calls.
package samples.quickstart.service.pojo;
import java.util.HashMap;
public class StockQuoteService {
private HashMap map = new HashMap();
public double getPrice(String symbol) {
Double price = (Double) map.get(symbol);
if(price != null){
return price.doubleValue();
}
return 42.00;
}
public void update(String symbol, double price) {
map.put(symbol, new Double(price));
}
}
You need to build the service definition file (StockQuoteService.aar) and
place it in "[Axis2_Home]/repository/services" directory in order to
deploy it as an axis2 service(Axis2 running in the standalone mode). If
axis2 runs inside a servlet engine like Apache
Tomcat relevant directory
should be "webapps/axis2/WEB-INF/services".
Axis2
quick start guide and
installation guide provides extensive details about creating and deploying services in different ways with Apache Axis2.
Since
our purpose is to test the state replication in Axis2 cluster, we
need to enable clustering from the axis2.xml in "[Axis2_Home]/conf"
directory. To deploy a axis2 cluster, two(or any other number) axis2
instances shoud be started, where "domain name" is set to same value and state replication property is enabled.
Make sure instances can communicate among each other, depending on the
membership scheme used for clustering.
If we deploy
the two instances in the same host, we need to change the "transport
listener" and "localMemberPort" as well. In this scenario transport
listener ports are set to "8080 and 8081" respectively in two axis2
servers which are running in the same local machine.
Start the axis2 servers as follows after configuring the axis2 cluster.
Then check to make sure that the service has been properly deployed
by viewing the list of services at,
Below is an snapshot of the browser in the above URL once you correctly deployed the service.
Figure 02. Deployed Axis2 services in the browser
Getting started with load Testing
a) Creating a test plan
Using the JMeter GUI, you can create various types of test plans
including, Web service test plan, Database test plan, FTP test plan etc.
Test
plan created trough the GUI is saved in .jmx format. Although test plan
can be edited by following the JMeter xml schema, modifying the test
plan using GUI is much easier.
In the landing view of JMeter, there are two basic elements. i.e Test plan and Work bench.
Right
click on the Test plan and add a Thread Group element. Create two
SOAP/XML-RPC Requests for two method calls associated with the
StockQuoteService service.
b) Configuring the test plan
In the Thread Group element, set the thread properties,
- Number of threads(users) : No. of concurrent users to be simulated.
- Ramp - up period(in seconds) :Time taken by the JMeter to invoke the threads
- Lop count : No of times the test plan should be repeated.
These properties can be varied depending on the requirements of the load test.
Shown below are the steps to follow while adding above elements.
Figure 03. Adding Thread group
Figure 04. Adding SOAP/XML-RPC request
In the "updatePrice request", set service URL and the SOAP action properties as shown below. Set SOAP/XML-RPC data as,
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://quickstart.samples/xsd">
<soapenv:Header/>
<soapenv:Body>
<xsd:update>
<!--Optional:-->
<xsd:symbol>?</xsd:symbol>
<!--Optional:-->
<xsd:price>${__Random(1,1000,)}</xsd:price>
</xsd:update>
</soapenv:Body>
</soapenv:Envelope>
Figure 05. updatePrice request view
Here, updatePrice request will be send to a one instance running on port "8080" and
the getprice request will be send to the other instance running on
"8081" to test the state replication property of the axis2 cluster.
Similarly, set the relevant properties in the "getPrice request" element. Set the XML-RPC Data as,
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://quickstart.samples/xsd">
<soapenv:Header/>
<soapenv:Body>
<xsd:getPrice>
<!--Optional:-->
<xsd:symbol>?</xsd:symbol>
</xsd:getPrice>
</soapenv:Body>
</soapenv:Envelope>
Figure 06. getPrice request view
Add
a timer to set the "thread delay time". This can be a constant time or
random timer such as "Gaussian random timer" to get a more realistic
behaviour of the system.
Figure 07. Adding a Timer Element
To
visualize the data, we can add Listeners like "Graph results",
"View Results in a table", "View results tree" and "Spline Visualizer".
In addition we can also send the responses of the service requests to a
file by adding a "Write results to a file" in the above element
properties. This is an essential feature for debugging and examining
errors.
c) Running the test plan
After
all the required fields in the test plan filled, save it. Run the test
plan from Run-->start or pressing ctrl+r. Use the "Graph results"
element to view the chart which is being populated when the load test
is running. Graph types like 'Data, average, throughput' can be enabled
in the chart to get a clear idea about the test results. Here throughput
means the number of requests processed by the server within a minute.
Figure 08. Graph results element view.
In the "View results in the table" element, status column illustrates whether service request completed successfully or failed.
Figure 09. View results in the table
To simulate high load on the server we can increase the no of threads and the loop count.
Once the test is done, "results.jmx" file will be created and this file can be used to visualize the results.
loadosophia is one of the sites which offers graph generation services using the XML/CSV results files from JMeter and many other file types such as Apache benchmark tool files etc. You can log into the site using Google account and it provides a workspace to maintain test results related to various projects. Upload the .jmx file and set of graphs will be generated against various parameters such as response time, throughput etc.
