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magro / memcached-session-manager

A tomcat session manager that backups sessions in memcached and pulls them from there if asked for unknown sessions
Apache License 2.0
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Validity data and session data have mismatching TTL #442

Open jungm opened 2 years ago

jungm commented 2 years ago

Session data appears to have a longer TTL in redis than validity data, causing issues with proper session expiration. The following line gets logged a couple hundred times before a java internal error appears, hinting at a StackOverflowError:

14-Feb-2022 14:21:34.684 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
14-Feb-2022 14:21:34.689 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
14-Feb-2022 14:21:34.695 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
14-Feb-2022 14:21:34.700 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
14-Feb-2022 14:21:34.705 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
14-Feb-2022 14:21:34.710 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
14-Feb-2022 14:21:34.715 WARNING [http-nio-8080-exec-4] de.javakaffee.web.msm.LockingStrategy.onAfterLoadFromMemcached No validity info available for session AB599463FEAA5BB99A84FF5FC48B2F26
*** java.lang.instrument ASSERTION FAILED ***: "!errorOutstanding" with message transform method call failed at ./src/java.instrument/share/native/libinstrument/JPLISAgent.c line: 873

Looking at the callstack this seems to be a side effect of running MSM in conjunction with Apache OpenWebBeans.

Session Manager Config:

    <Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager"
             memcachedNodes="redis://localhost:6379"
             sticky="false"
             sessionBackupAsync="false"
             sessionBackupTimeout="1000"
             requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js|html|htm|woff).*"
             storageKeyPrefix="context"/>

Redis version: 6.2.6

Jedis version: 3.8.0

memcached-session-manager version: 2.3.2

This is what the issue looks like in the redis CLI:

127.0.0.1:6379> KEYS *
1) "AB599463FEAA5BB99A84FF5FC48B2F26"
2) "validity:AB599463FEAA5BB99A84FF5FC48B2F26"
127.0.0.1:6379> TTL validity:AB599463FEAA5BB99A84FF5FC48B2F26
(integer) 42
127.0.0.1:6379> TTL AB599463FEAA5BB99A84FF5FC48B2F26
(integer) 101

This appears to be caused by this line, though I'm not sure if this multiplication was implemented intentionally