@Override
  public ByteBuffer processBinaryStorageCommand(Object key, byte[] value, long cas, int flags,
      Cache cache, RequestReader request) {
    ByteBuffer response = request.getResponse();
    Region<Object, ValueWrapper> r = getMemcachedRegion(cache);
    ValueWrapper val = ValueWrapper.getWrappedValue(value, flags);
    boolean success = true;

    try {
      if (cas != 0L) {
        ValueWrapper expected = ValueWrapper.getDummyValue(cas);
        success = r.replace(key, expected, val);
      } else {
        r.put(key, val);
      }

      if (getLogger().fineEnabled()) {
        getLogger().fine("set key:" + key + " succedded:" + success);
      }

      if (success) {
        if (isQuiet()) {
          return null;
        }
        response.putShort(POSITION_RESPONSE_STATUS, ResponseStatus.NO_ERROR.asShort());
        response.putLong(POSITION_CAS, val.getVersion());
      } else {
        response.putShort(POSITION_RESPONSE_STATUS, ResponseStatus.KEY_EXISTS.asShort());
      }
    } catch (Exception e) {
      response = handleBinaryException(key, request, response, "set", e);
    }
    return response;
  }
general format of the command is: <code>
&lt;command name&gt; &lt;key&gt; &lt;flags&gt; &lt;exptime&gt; &lt;bytes&gt; [noreply]\r\n
</code><br>

"set" means "store this data".
geode-memcached/src/main/java/org/apache/geode/internal/memcached/commands/SetCommand.java