1. The phenomenon was reproduced at lab, the probability of its occurrence is around 20%.
2. After sending the operation log collected from U2000 LCT and database to H&Q for analysis, from the log files some exception info can be found as below:
1) MCDB process start log
vendorError2[-1]=[Microsoft][ODBC SQL Server Driver][SQL Server]Cannot open database "MCDB" requested by the login. The login failed.
(Remark: MC is a process about interprocess message distribution.)
2) Client log
[pool-5-thread-50]5-8-2012 20:32:14 | ERROR | CommonDataMgr | getProcessInfoList(char) | Message not success send , result :184549395
(Remark: It shows “Message not success send”.)
Till then, we draw a conclusion that the MC process failed to connect to the MCDB, which affect the interprocess communication, and this caused the behavior.
The below diagram shows the analysis result, how this phenomenon occurs when the user start Win7 OS and login the U2000LCT client.
3. R&D setup the mirror environment at H&Q, and the behavior also was reproduced. And the behavior can not be observed at windows XP&SQL Edition environment.
4. From the DB log, we found some records about the DB connection, which can support the previous conclusion.
2012-05-18 19:03:49.64 spid73 Starting up database 'imaptempdb'.
2012-05-18 19:03:49.68 spid109 Starting up database 'imapsmdb'.
2012-05-18 19:03:53.16 Logon Error: 18456, Severity: 14, State: 38.
2012-05-18 19:03:53.16 Logon Login failed for user 'NMSuser'. Reason: Failed to open the explicitly specified database. [CLIENT: 127.0.0.1].
5. Based on the database log, R&D found that the start mode of “SQL2008 Express edition” is different with other “SQL Edition”.
6. Microsoft confirmed that the user database (such as MCDB) start mode in latest SQL2008 express edition is different from other SQL edition; the user database will not start with the SQL process in Express edition, which may bring in the DB connection failure.The user database will be triggered to start by DB visit on it.