Logging and Debugging

Logging

Invocation Grid Worker Logger

A worker process will be decompressed to a temporary directory on ScaleOut hosts when it is deployed, located under the following path:

Windows: %ProgramData%\ScaleOut Software\IG
Linux: /usr/share/ScaleOut Software/IG

The Invocation Grid project template provides a Microsoft.Extensions.Logging ILogger instance to PMI callbacks like the one implemented in Creating an Invocation Grid Project.

By default, this ILogger instance is configured to write log entries to rolling log files in IG's temporary directory on the ScaleOut hosts. The "ShoppingCartIG" worker used in these samples would have its log files written to this location:

Windows: %ProgramData%\ScaleOut Software\IG\ShoppingCartIG\log20210727.txt
Linux: /usr/share/ScaleOut Software/IG/ShoppingCartIG/log20210727.txt

These log files are the first place to check if an IG fails to launch or does not behave as expected.

ScaleOut Service Logging

Less commonly, the ScaleOut service itself may fail to launch an IG worker. This may be due to packaging errors, permission errors on the file system, or low-level problems with the platform. In this case, the service will write error information to the server logs.

Windows: C:\Program Files\ScaleOut_Software\StateServer\soss_tlog0.txt
Linux: /var/log/soss/soss_tlog0.txt

While the service log files contain a lot of internal diagnostics, all entries related to launching an IG will begin with the text SOSS client lib: [L] IG Bootstrapper. For example:

21/07/30 17:09:31 - SOSS client lib: [L] IG Bootstrapper: Starting IG 'ShoppingCartIG'
                    (2104209428) | File: dotnet | Args: ShoppingCartIG.dll | 
                    Local server port: 721 | WorkingDir: 
                    C:\ProgramData\ScaleOut Software\IG\ShoppingCartIG\dvipo5_xUgExRQDg

Debugging an IG

When running on a local development machine, use the -l flag with the ig start command to instruct the local ScaleOut service to launch your IG project straight out of the project's Debug build folder. This skips the packaging and deployment step:

ig start -c "bootstrapGateways=localhost:721" -l

There are several ways to attach a debugger to the IG process:

In Visual Studio's Debug menu, select the "Attach to Process..." item and select the dotnet.exe process that hosts your worker from the list.
Manually trigger a breakpoint by adding a call to System.Diagnostics.Debugger.Launch() in Program.Main().

Note