Infinispan Rest API 1; Hotrod API 0

[arcanemage]

Infinispan 9 offers REST API out-of-the-box, which I was delighted with until I attempted to read the distributed cache via the Hotrod API.

This is the problem: Used REST API to populate the cache, then attempt to read that content using the Java Hotrod API. In Java, the keys are accessible, but not their values . For example:

The following XML was POSTed successfully with the URI: http://localhost:8080/rest/default/156211. Issuing a GET returns the aforementioned XML content too.

<catalog>

   <book id="book01">

      <author>Gambardella, Matthew</author>

      <title>XML Developer's Guide</title>

      <genre>Computer</genre>

      <price>44.95</price>

      <publish_date>2000-10-01</publish_date>

      <description>An in-depth look at creating applications

      with XML.</description>

   </book>

</catalog>

However, when using the following Java code:

import org.infinispan.client.hotrod.RemoteCache;

import org.infinispan.client.hotrod.RemoteCacheManager;

import org.infinispan.client.hotrod.configuration.ConfigurationBuilder;

import org.infinispan.client.hotrod.impl.ConfigurationProperties;

public static void  main (String[] args) throws ExecutionException, InterruptedException {

  ConfigurationBuilder builder = new ConfigurationBuilder();

  builder.addServer().host("127.0.0.1").port(ConfigurationProperties.DEFAULT_HOTROD_PORT);

  RemoteCacheManager cacheManager = new RemoteCacheManager(builder.build());

  RemoteCache<Object, Object> cache = cacheManager.getCache();

  Set<Object> keySet = cache.keySet();

  Iterator<Object> i = keySet.iterator();

  System.out.println("============= SESSION");

   while (i.hasNext()) {

  Object key = i.next();

  System.out.println("> key=" + key);

  System.out.println("> value=" + cache.get(key));

  System.out.println("");

  }

  System.out.println("=============");

}

The output is:

============= SESSION
> key=156211
> value=null

=============

Can anyone enlighten me as to why this occurs?

[gustavonalle]

The Hot Rod and Rest endpoints have different expectations on how data is stored and read back, it's not possible (out-of-the box) to fully read data written by rest from Hot Rod and vice-versa.

At the moment there is no way of asking for an specific format via Hot Rod (this is work in progress), so the only way to make both endpoints work together is to enable compatibility mode, e.g.:

<local-cache name="my-cache">

       <compatibility enabled="true" />

</local-cache>

[arcanemage]

Thanks for the quick reply, Gustavo.

As recommended I switched on the compatibility mode, but now the output looks like this:

============= SESSION
> key=156211
> value=[B@7921b0a2

=============

Does this meant some kind of serializer/deserializer is required?

Many thanks for your response.

[sebastian.laskawiec]

You will also need a custom marshaller.

[gustavonalle]

What kind of objects are you writing to the cache? If you are writing strings or primitives, it should work without extra serializers/deserializers.

[arcanemage]

Hi Gustavo,

I am writing strings (XML); Content type="application/xml" -- see my original post.

Cheers

[gustavonalle]

This is a bug. You should be able to get the XML from Hot Rod. Opened [ISPN-7991] Compatibility between Rest and HotRod not working on both ways - JBoss Issue Tracker

[gustavonalle]

Hello arcanemage, the bug should not affect version 9.0.0.Final, but is present on 9.1.x pre-release version.

You should be able to support your use case by following the instructions on [ISPN-7991] Improve Compatibility between Rest and HotRod for text content - JBoss Issue Tracker

The extra step of creating a custom marshaller and deploying it will not be necessary in the version 9.1.0.Final, to be released this Friday.