Disable Only HealthCheck Related Logging

Question

I'm trying to figure out a way to disable any health-check related ILogger logging. I am aware of LogLevel filtering, but that will not work here.

As an example, I have a healthcheck that makes an outbound call to a RabbitMQ metrics API. This results in an outbound http call with every inbound call to /health. In general, I want to log all outbound calls made using the HttpClient, but that log is now full of this particular log entry:

[2021.06.15 13:57:04] info: System.Net.Http.HttpClient.Default.LogicalHandler[101] => ConnectionId:0HM9FV5PFFL5K => RequestPath:/health RequestId:0HM9FV5PFFL5K:00000001, SpanId:|6726c52-4217ec92de4df5fb., TraceId:6726c52-4217ec92de4df5fb, ParentId: => Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckLogScope => HTTP GET http://rabbitmq/api/queues/MyVHost/MyQueue?msg_rates_age=60&msg_rates_incr=60 : End processing HTTP request after 4.6355ms - OK

So, I could apply a warning filter to the HttpClient/LogicalHandler to remove those entries, but then I'd be removing all the info logs of other outbound Http requests, which I don't want.

So, basically, I need a smarter filter that can look at the scopes (or even the text in certain cases), and can filter out based on "Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckLogScope". That doesn't seem to be possible though, as the filter callback doesn't provide those details.

Does anyone have any idea how to do more specific log filtering for cases like this?

I have looked at .net core log filtering on certain requests, but extending every ILoggerProvider I use isn't possible, since some are not public classes.

Has anyone found a way , we are dropping Serilog now since you log to console in k8 — user1496062, Mar 29 '22 at 23:03

score 0 · Answer 1 · answered Jan 04 '22 at 08:28

You could use Serilog for logging, as it also provides great filtering, enriching, and formatting capabilities with Serilog.Expressions Nuget package.

There is even a simple example provided in the link above for filtering health checks, which fulfilled my needs to fully filter out health check logging based on the request path '/health'. Following the guide, it only required adding appsettings.json configuration, after the serilog was configured as the application logger to make it work:

{
 "Serilog": {
    "Using": ["Serilog.Expressions"],
    "Filter": [
      {
        "Name": "ByExcluding",
        "Args": {
          "expression": "RequestPath like '/health%'"
        }
      }
    ]
  }
}

Quite heavy evaluation on each log – user1496062 Feb 28 '22 at 05:12 — user1496062, Feb 28 '22 at 05:12

score 0 · Answer 2 · answered Nov 03 '22 at 15:32

To filter out those requests you can try using the Log4Net StringMatchFilter filter with the value of the health URL. Here is the code for the configuration file if health URL is just localhost/health:

<filter type="log4net.Filter.StringMatchFilter">
    <stringToMatch value="/health" />
    <acceptOnMatch value="false" />
</filter>

Disable Only HealthCheck Related Logging

2 Answers2