Tweak loading times of Jersey over AppEngine

Question

my application service is not able to start or respond to even warmup requests as the time taken by Jersey to scan the libraries is inordinate.

I have created application and hardcoded all the paths of the Resources for jersey.

<servlet-name>Jersey REST Service</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.livily.rest.JerseyApplication</param-value>
</init-param>

Jersey Application has all the classes

public Set<Class<?>> getClasses()
{
Set<Class<?>> s = new HashSet<Class<?>>();
s.add(com.livily.rest.visitor.UserRatingUtil.class);
}

However, jersey is scanning for lot of providers

Mar 8, 2013 3:39:40 PM com.sun.jersey.core.spi.component.ProviderServices getServiceClasses
CONFIG:     Provider found: class com.sun.jersey.server.impl.model.parameter.multivalued.StringReaderProviders$StringConstructor

It is doing it about 50-100 times and then

Mar 8, 2013 3:39:41 PM com.sun.jersey.server.impl.modelapi.annotation.IntrospectionModeller createResource
FINEST: A new abstract resource created by IntrospectionModeler: AbstractResource("/current-status", - CurrentStatus: 1 constructors, 0 fields, 0 setter methods, 1 res methods, 0 subres methods, 0 subres locators )

for each one

The time taken in total is about 4-10 secs and appengine does not like this as it expects to wrap up the loading quickly; otherwise it starts giving weird 500 errors (for even static files).

I am stumped; any help will be appreciated.

Expostulation

Not an answer, but I had similar load time issues with jersey and I moved to RestExpress (github.com/RestExpress/RestExpress), which doesn't have any of the J2EE weight. – Disafforest

Cloudpre - that's not a valid comment – Disafforest

Lipis - I moved to restexpress and to my surprise, it was actually slower in load time. I still get deadline exceptions. What is the best way to figure out what is taking lot of startup time? I changed logger level to all and find lot of output. Is this the best way? – Expostulation

what other libraries are you using? – Disafforest

appengine, apps-marketplace, appengine-api-labs, guava, jackson-mapper, resteasy, joda-time-1.6, jsoup, commons-lang, objectify (about 20 registrations), jackson-core, openid4java, gson, mustache-compiler, scannotation, jsr107cache, commons-logging, asm. Nothing unusual. I use 1.7.5 and jar all the classes under WEB-INF. – Expostulation

Moving to F4 is one workaround for this mid-size app. – Expostulation

Answer 1

I use the packages property to name which packages should be scanned as follows...

    <init-param>
         <param-name>com.sun.jersey.config.property.packages</param-name>
         <param-value>com.foo.myproviders</param-value>
    </init-param>

Valentia

Jaytee - packages scanning are in fact slower than explicit defining the classes in the JaxRS Application. – Expostulation

how can you explicit define the classes in JaxRS Application? I thought the package scanning was the only possibility – Wrac

Answer 2

Set jersey.config.disableAutoDiscovery. See Configuration Properties for details.

<init-param>
    <param-name>jersey.config.disableAutoDiscovery</param-name>
    <param-value>true</param-value>
</init-param>

Dittmer