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From: James Y. <ji...@yo...> - 2007-08-21 16:40:38
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Harris, Jeff wrote: > Does anyone know the effect of lowering the MULTI_CACHE_ROUTE_TTL > constant in multi.h from 60 seconds to say 10? Will it cause extra > network traffic or anything if the routes are purged more often? > > I am trying to work around an issue I'm seeing with spikes in the number > of multi_instance objects. I have 125 connected clients and after a > number of restarts of all the clients, the number of multi_instance > objects on my server spikes to over 600 leading to an eventual > exhaustion of memory. I am using keep-alive settings of 5 second pings > and 30 seconds of inactivity. > > Lowering the value to 30 seems to hold off the spikes for a bit. With a > value of 10 I have not seen the spikes. > > Any help would be appreciated. > > OpenVPN caches routes in a hash table for efficiency, so that it doesn't need to iterate through the whole routing table in order to find a match. The problem appears to be that cache entries may prolong the life of a marked-for-delete multi-instance object by holding references to it until the cache entry expires. So timing out the cached routes earlier appears to be a good solution, and will not increase network traffic. James |