I am logging events of all types to single Json file irrespective of LogLevel. Now I have a requirement to log some custom performance counters to a seperate Json file. How can this be done in Serilog. Should I create different Logger Instance and use that where ever I am going to Log the performance counters? Want to use this with LibLog
Answer
You can do this by first making sure the performance counter events are tagged with either a particular property value (OpenMappedContext() in LibLog) or from a particular type/namespace.
var log = LogProvider.For<MyApp.Performance.SomeCounter>()
log.Info(...);
When configuring Serilog, a sub-logger with filter applied can send just the required events to the second file.
Log.Logger = new LoggerConfiguration()
.WriteTo.Logger(lc => lc
.Filter.ByExcluding(Matching.FromSource("MyApp.Performance"))
.WriteTo.File("first.json", new JsonFormatter()))
.WriteTo.Logger(lc => lc
.Filter.ByIncludingOnly(Matching.FromSource("MyApp.Performance"))
.WriteTo.File("second.json", new JsonFormatter()))
.CreateLogger();