ArangoDB failed to start suddenly

Question

I have been evaluating for couple of days on ArangoDB. However, today after I backed from my lunch, I figured out my ArangoDB in my devopment machine is not working anymore. I have no clues on what's happening. Before this it was working fine. It happened when I backed from lunch and tried to access the localhost:8529 web ui but not successful and I tried to restart the windows and the OS prompted me to update and restart. After restarting, i could not start the Arango Web Interface also.

I tried restart the Arango service but seems like not success. For your information, I am using Windows 8.1. My ArangoDB version is 2.3.4. I also tried to use the console command arangod. This is what I can see now.

C:\Program Files\ArangoDB 2.3.4\bin>arangod
2015-01-17T06:59:18Z [6980] INFO ArangoDB 2.3.4 64bit -- ICU 52.1, V8 3.16.14, O
penSSL 1.0.1g 7 Apr 2014
2015-01-17T06:59:18Z [6980] INFO using default language 'en'
2015-01-17T06:59:18Z [6980] INFO loaded database '_system' from 'C:\Program File
s\ArangoDB 2.3.4\var\lib\arangodb\databases\database-76067'
2015-01-17T06:59:18Z [6980] INFO loaded database 'trial_sample' from 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-950557092131'
2015-01-17T06:59:18Z [6980] INFO loaded database 'ab0fa822-9bfc-4b70-8a8b-637a45
c9794f' from 'C:\Program Files\ArangoDB 2.3.4\var\lib\arangodb\databases\databas
e-1033499126051'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1033995233571'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1033995233571'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034030819619'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034030819619'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034075056419'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034075056419'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034110642467'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034110642467'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034163923235'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034163923235'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034199509283'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034199509283'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034272188707'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034272188707'
2015-01-17T06:59:18Z [6980] INFO found dropped database in directory 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034318719267'
2015-01-17T06:59:18Z [6980] INFO removing superfluous database directory 'C:\Pro
gram Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034318719267'
2015-01-17T06:59:18Z [6980] INFO loaded database 'Test_Sample5' from 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1034354305315'
2015-01-17T06:59:18Z [6980] INFO loaded database 'Test_Sample2' from 'C:\Program
 Files\ArangoDB 2.3.4\var\lib\arangodb\databases\database-1037196339491'
2015-01-17T06:59:18Z [6980] INFO running WAL recovery
2015-01-17T06:59:18Z [6980] INFO replaying WAL logfile 'C:\Program Files\ArangoD
B 2.3.4/var/lib/arangodb\journals\logfile-866004314403.db'
2015-01-17T06:59:18Z [6980] INFO replaying WAL logfile 'C:\Program Files\ArangoD
B 2.3.4/var/lib/arangodb\journals\logfile-920351418659.db'
2015-01-17T06:59:18Z [6980] WARNING database 887677462819 not found
2015-01-17T06:59:18Z [6980] WARNING database 887677462819 not found
2015-01-17T06:59:18Z [6980] WARNING database 887677462819 not found
2015-01-17T06:59:18Z [6980] WARNING database 887677462819 not found
2015-01-17T06:59:18Z [6980] WARNING database 887677462819 not found
2015-01-17T06:59:18Z [6980] WARNING database 887677462819 not found

It looks like very serious problem for me. I plan to put ArangoDB into production in the future after the evaluation. I just afraid this issue will happen in my production server. Any help will be very much appreciated.

Answer 1

The output is unfortunately very misleading. The test data created and deleted a lot of databases and collections. These two operations are really expensive and take a lot of time to recover. In normal operations this is not a problem, because you would not create 100 databases in a run. But during testing this can happen. The effect is two fold: warning are printed during recovery, which are not really correct. The collection/database was indeed removed. We fixed this in the ArangoDB 2.4 release. Secondly, it takes a long time to recover, because the operations are expensive.