How to control the okHttpClient connections size?
<p>I am debugging an issue in my android app. I found the root cause is file descriptors went beyond the limit. After further investigation I found that the app has too many sockets open. I use OkHttpClient 2.5 for all of my network communication, thus I am wondering how should I limit my connection pool size. Below is my code snippet:</p>

<pre><code>    OkHttpClient okHttpClient = new OkHttpClient().setConnectTimeout(TIMEOUT);
    ConnectionPool connectionPool = new ConnectionPool(MAX_IDLE_CONNECTIONS,
                                                       KEEP_ALIVE_DURATION_MS);
    okHttpClient.set(connectionPool);

    @RequireArgsConstructor
    public HttpEngineCallable implements Callable&lt;IHttpResponse&gt;
    {
      private final String url;

      public IHttpResponse call () throws Exception 
      {
         try
        {
           Request request = Request.Builder().url(url).build();
           Call call = okHttpClient.newCall(request);
           Response rawResponse = call.execute();
           return new OkHttpResponse(rawResponse);
        }
        catch (Exception e)
        {
           throw new IllegalStateException(e);
        }
    }  

    private final Function&lt;IHttpResponse, T&gt; httpResponseParser = new Function&lt;IHttpResponse, T&gt;()
    {
        @Nullable
        @Override
        public T apply(@Nullable IHttpResponse httpResponse)
        {
            if(httpResponse == null)
            {
               return null;
            }

            InputStream stream = httpResponse.getBody();
            JsonParser parser = null;
            T result = null;

            try
            {
               parser = jsonFactory.createParser(stream);
               result = strategy.parseData(parser);
            }
            catch (Exception e)
            {
               log.error("Unable to convert {} with {}.", stream, strategy, e);
            }
            finally
            {
               IOUtils.closeQuietly(parser);
               IOUtils.closeQuietly(stream);
            } 

          return result;
        }
     };

     Future&lt;T&gt; future = executorService.submit(new HttpEngineCallable(url));
     Future&lt;V&gt; finalFuture = Futures.transform(future, httpResponseParser, executorService);

     T result = timeoutExecutorService.submit(new Runnable() 
     {
        try
        { 
          T result = finalFuture.get(CLIENT_TIMEOUT, TIMEUNIT)
          if (result == null)
          { 
            notify onFailure listeners
          }
          else
          {
            notify onSuccess Listeners
          }
        }
        catch(Exception ex)
        {
          notify onFailure listeners
        }
     } 
</code></pre>

<p>So I have a few questions regarding this implementation:</p>

<ol>
<li>My CLIENT_TIMEOUT is shorter than OkHttp ConnectTimeout. If my <code>finalFuture.get(CLINT_TIMEOUT, TIMEUNIT)</code> throws timeout exception, would my finally block in the Parser Function still be executed? I am counting on it to close my connection. </li>
<li>How can limits the size of my ConnectionPool? Is there way I can auto-recycle oldest connections if connection went beyond limit?</li>
</ol>