How can I read MATLAB Web App Server logs?

I am using MATLAB Web App Server R2023b and would like to understand the information captured in the server log files. What information can be obtained from these logs, and how should I be interpreting the log output?

Answer 1

[MathWorks Support Team]

The information below provides a general guideline for reading MATLAB Web App Server server logs. This information is for release R2023b and may vary in other releases.

How do I read Web App Server log files?

Log files can be found in the "logs" directory on the server machine. Note that these files contain sensitive server- and client-side information and may only be accessible to a user with administrator privileges.

Each line of the main logs contains a capital letter, for example “agent::staticcontent

E

home/customization/header_logo.png does not exist”, or “agent::mdwas

V

Service stopped: processcontrol”. These letters correspond to log line type:

• D : data - content of packets, streams, files, etc.
• P : parameter - function arguments
• G : debug - verbose debugging output
• I : info - data/values representing normal operation
• V : event - significant control-flow decisions, connection set-up or tear-down, module initialization, etc.
• > : scope_entry - function entry
• < : scope_exit - function exit
• R : return_value - function return value
• W : warning - conditions which are unexpected or anomalous but which do not halt execution
• E : error - failures which prevent the current request, operation, command, etc. from completing correctly but which do not compromise the over-all integrity of the process
• C : critical - failures and/or conditions under which continued correct and well-defined execution is no longer possible
• F : fatal - failures and/or conditions under which continued correct and well-defined execution is no longer possible; unconditionally aborts program execution

What should I look for when reading logs for troubleshooting purposes?

When debugging, you should mainly focus on letters "E - error", "C - critical" and "F - fatal" for errors.

Letters "G - debug" and "I - info" only show in the logs if the logging level is set to "verbose".

Can I get app usage information from the logs?

The webapps_launcher_<timestamp>.log file records information on each app session, including the specific app being launched and the runtime version used.

When should I use "verbose" logging?

“Normal” logging level should be sufficient for most cases. Running at verbose level is not recommended since it is less performant and captures sensitive server- and client-side information.

"Verbose" logging may be useful when troubleshooting issues that do not appear in normal logs, or when error output in the normal logs is not sufficient to troubleshoot an issue. For example, when troubleshooting authentication issues, verbose logs may reveal more process information:

Normal Log:00001147 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation V AuthNZ Event: jdoe logged in.
Verbose Log:00001119 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G LDAPFilter::in
00001120 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Host: localhost
00001121 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Port: 10636
00001122 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Username: jdoe
00001123 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Searcher DN: 
00001124 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Base DN: ou=Users,dc=example,dc=com
00001125 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G User filter: (&(objectClass=inetOrgPerson)(uid=jdoe))
00001126 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap init
00001127 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap set ldap version option
00001128 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Check SSL CA: false
00001129 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Checking if SSL is enabled
00001130 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I SSL is not enabled yet. Enable SSL.
00001131 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Not verify server cert 
00001132 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap connect
00001133 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Binding ldap
00001134 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap bind
00001135 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap search
00001136 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Succeeded to get entry
00001137 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Start authenticating user name and password
00001138 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap init
00001139 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap set ldap version option
00001140 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation G Check SSL CA: false
00001141 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Checking if SSL is enabled
00001142 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I SSL is not enabled yet. Enable SSL.
00001143 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Not verify server cert 
00001144 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Success of ldap connect
00001145 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Succeeded to authenticate user name and password
00001146 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation I Get authenticated user's attributes
00001147 2023-11-10 15:39:09 0x000010e0 agent::mdwas::translation V AuthNZ Event: jdoe logged in.

Additionally, verbose logs should be provided whenever contacting MathWorks Technical Support.