public ClientCacheFactory setPoolPingInterval(long pingInterval) {
    getPoolFactory().setPingInterval(pingInterval);
    return this;
  }
How often to ping servers to verify that they are still alive. Each server will be sent a ping
every pingInterval if there has not been any other communication with the server.
<p>
These pings are used by the server to monitor the health of the client. Make sure that the
pingInterval is less than the maximum time between pings allowed by the cache server.

@param pingInterval The amount of time in milliseconds between pings.
@return a reference to <code>this</code>
@throws IllegalArgumentException if <code>pingInterval</code> is less than or equal to
        <code>0</code>.
@see CacheServer#setMaximumTimeBetweenPings(int)
geode-core/src/main/java/org/apache/geode/cache/client/ClientCacheFactory.java