問題

When user credentials are entered and Log in is clicked, the login page reloads without showing any errors.

Symptoms & diagnosis

The above symptom usually indicates that Redis (redisserver) is down.  This can be checked by running the following command from the Hipchat Server command line.  The command will return nothing: 

ps -ef | grep localhost:6379

Attempting to start the Redis service (redisserver) manually by running: 

sudo dont-blame-hipchat
/etc/init.d/redisserver start

....results in the following error in /var/log/redis-server.log:

Short read or OOM loading DB. Unrecoverable error, aborting now

原因

The issue will occur when Redis tries to load the data from the backup in the file system into memory. This only happens under very specific circumstances, for example, following a migration of Hipchat Server from one server instance to another. 

The root cause of the issue is still unknown at the moment.

回避策

Remove the backup file and attempt to start Redis:

sudo dont-blame-hipchat
rm /file_store/redis/dump.rdb
/etc/init.d/redisserver start

既知の問題

Removing the Redis backup in the steps above will clear all of the data in Redis, so users will lose their auto-join information and their client appearance settings. Users will not lose their room memberships. If the old Hipchat Server instance is still up, the old Redis data can be backed up and copied over to the new instance using the commands below: 

Old instance

for key in $(redis-cli KEYS "pref:*" | sed 's/^[1-9][0-9]*) //g'); do echo "[$(date +%Y-%m-%dT%H:%M:%S)] Exporting $key"; redis-cli GET $key > ${key}.value; done
tar czvf redis_exports.tgz pref:* 

New instance

After transferring redis_exports.tgz to the instance, run: 

tar xzvf redis_exports.tgz
for file in `ls *.value`; do key=`echo $file | cut -d"." -f1`; echo "[$(date +%Y-%m-%dT%H:%M:%S)] Import $key from $file"; redis-cli SET $key "`cat $file`"; done