Phenomenon

When an environment suddenly finds that it cannot connect to the database, it uses JDBC or trafci to connect to the database. The error is as follows:

*** ERROR[8837] Internal error occurred. User: XXX

Analysis

Error [8837] internal error occurred Generally, there is a problem with the authentication of the connection between the database and LDAP
therefore, after encountering this error, first, we can use the LDAP check command to check whether the database user can be queried from LDAP normally. The command is:

ldapcheck --username=trafodion

If the above command returns result 2, it indicates that trafodion accesses LDAP abnormally,

Lookup request: externalName trafodion, configNmae 'not available' (ConfigNumber -2), result 2(Unexpected error returned from LDAP)

After encountering the above errors, the next step is to check whether the LDAP service is normal
first, we need to find out which machine the LDAP service is on
This can be found through the .traf_authentication_config file in the cdc directory, which can be viewed by executing the following command using the trafodion user.

cdc
cat .traf_authentication_config

The value of the LDAPHostName parameter in the .traf_authentication_config configuration file is the LDAP node used by the database.
Once we find the node where LDAP is located, we can log in to the corresponding node to check if the LDAP service is working.

service slapd status

If it is found that the slapd service is not opened, we can open the LDAP service with the following command,

service slapd start

Of course, another is that the LDAP service is started, but the reason for the exception is that there are too many open files. For this scenario, you can modify Max open files to modify the number of open files of LDAP.