[sr-dev] [kamailio] rtpengine: hash table implementation with entry expire

Hello, We are working to improve the rtpengine module node selection mechanism. Right now, the selection is stateless, and assumes that rtpengine machines don't often break. Our idea is to maintain a "callid(key)<->node(value)" global shared hash table with a global lock. When the "offer" comes, a new entry is inserted in the hash table. When subsequent commands come (e.g. "answer", "delete") the lookup is done and the specific node is selected. When the "delete" comes, the entry is freed from the hashtable. We've already implemented most of the rtpengine hash table API. The question is, if _no_ "delete" comes, how to eventually free the old entries? The idea is to introduce a modparam for a hastable entry timeout and: 1: create a separate process that looks into the hashtable and does the cleanup or 2: every time an insert/remove/lookup in the table is done, on the way of doing the action, check also for expired entries and free them. (this will free only the expired entries in the list at index=hash(callid) but will prevent the hash table growing too big) What do you think about the whole hashtable idea? And how about the expired entries deletion? Do you have any other advices/proposals? Best Regards, 1&1 Team