I've been fiddling with this issue on my server as well, and I can confirm that swapping x64/x86, Java 7/Java 8, or JRE/JDK does not seem to fix the issue. I have two friends in particular that have this issue about twice a night, but the other 5 or so online will not have any issues until the 2 others join, and then everyone is hit with massive lag.
Server reboots fix the issue temporarily, but I'm not always around to reboot things for them. This issue is causing a lot of problems for our small group of friends. Really hope someone gets around to fixing it soon, or providing a valid work around.
As another side note, memory allocation to the server doesn't fix it either. I've been playing around with the java flags on server start, and none of them seem to help either (either with absolutely nothing or -Xmn1G -Xss4M -Xmx2G -Xms2G -jar minecraft_server.1.8.jar -d64 -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=8 -XX:+AggressiveOpts -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+UseFastAccessorMethods -XX:+OptimizeStringConcat -XX:+UseBiasedLocking -Xincgc -XX:MaxGCPauseMillis=10 -XX:SoftRefLRUPolicyMSPerMB=10000 -XX:+CMSParallelRemarkEnabled -Djava.net.preferIPv4Stack=true). I'd gladly test out anyone else's ideas as I myself have ran out.
Jerky
I've been fiddling with this issue on my server as well, and I can confirm that swapping x64/x86, Java 7/Java 8, or JRE/JDK does not seem to fix the issue. I have two friends in particular that have this issue about twice a night, but the other 5 or so online will not have any issues until the 2 others join, and then everyone is hit with massive lag.
Server reboots fix the issue temporarily, but I'm not always around to reboot things for them. This issue is causing a lot of problems for our small group of friends. Really hope someone gets around to fixing it soon, or providing a valid work around.
As another side note, memory allocation to the server doesn't fix it either. I've been playing around with the java flags on server start, and none of them seem to help either (either with absolutely nothing or -Xmn1G -Xss4M -Xmx2G -Xms2G -jar minecraft_server.1.8.jar -d64 -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=8 -XX:+AggressiveOpts -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+UseFastAccessorMethods -XX:+OptimizeStringConcat -XX:+UseBiasedLocking -Xincgc -XX:MaxGCPauseMillis=10 -XX:SoftRefLRUPolicyMSPerMB=10000 -XX:+CMSParallelRemarkEnabled -Djava.net.preferIPv4Stack=true). I'd gladly test out anyone else's ideas as I myself have ran out.