f7744b72_e__8_0_24____The_AJP_Connector__Description
[Attribute] processorCache [Description] 
The protocol handler caches Processor objects to speed up performance. This setting dictates how many of these objects get cached. -1 means unlimited, default is 200. If not using Servlet 3.0 asynchronous processing, a good default is to use the same as the maxThreads setting. If using Servlet 3.0 asynchronous processing, a good default is to use the larger of maxThreads and the maximum number of expected concurrent requests (synchronous and asynchronous).
Apache Tomcat 8 Configuration Reference (8.0.24) - The AJP Connector