Shared property not working

Im trying to write logs and have the UI read them simultaneously, but when I call File.Open(Path.Combine(directory, fileInfo.Name), FileMode.Open, FileAccess.Read)) it throws an exception and the file is already being used by a process.

The log is configured as such: sublogger -> filter -> sinks.map -> sinks.async -> sinks.file So logged items are logged to a uniquely named file filtered by their type and written asynchronously.

Config code:

          public SerilogProvisioner(LoggerConfiguration configuration, LogConfigResolver logConfigResolver, 
         string rootPath)
        {
            Relay = new LogRelay();
            LogConfigResolver = logConfigResolver;

            foreach (var key in logConfigResolver.GetTypes())
            {
                var resolution = logConfigResolver.Resolve(key);

                if (resolution != null && resolution.Output != null)
                {
                    configuration = configuration
                        .WriteTo.Logger(lc => lc
                            .Filter.ByIncludingOnly(Matching.FromSource(key.FullName))
                            .WriteTo.Map(resolution.PropertySelector ?? "LogId", (property, wt) =>
                            {
                                var logOptions = logConfigResolver.Resolve(key);
                                var path = Path.Combine(rootPath, logOptions.Output.Uri, property + "-.txt");

                                var logId = new LogId(key, property);
                                var relaySink = new LogRelaySink(logId, Path.Combine(rootPath, logOptions.Output.Uri));
                                Relay.AddRelay(relaySink);

                                switch (logOptions.Output.OutputType)
                                {
                                    case LogOutputType.File:
                                        wt.Async(a => a.File(
                                            path,
                                            shared: true,
                                            rollingInterval: RollingInterval.Day));
                                        break;
                                }

                                wt.Sink(relaySink);
                            }));
                }
            }
`

[jaksonlin]

Hit the same issue when we do read all lines of the log file or using file stream without adding FileShare.ReadWrite:

Logger Configuration:

    logger = new LoggerConfiguration()
            .MinimumLevel.ControlledBy(loggingLevelSwitch)
            .Enrich.WithProperty("Component", component)
            .WriteTo.Console(outputTemplate: "{Timestamp:HH:mm:ss} [{Component}][{Level}] {Message}{NewLine}{Exception}")
            .WriteTo.File(logFile, shared:true, outputTemplate: "{Timestamp:HH:mm:ss} [{Component}][{Level}] {Message}{NewLine}{Exception}")
            .WriteTo.Logger(sLogger)
            .CreateLogger();

Code that hit this bug (file refer to the log file user trying to read):

    string[] result1 = File.ReadAllLines(file);  <--- this won't work
    using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))<---this won't work

W/A for this bug:

    using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))

Add FIleShare.ReadWrite

[mpowrie]

I find that real-time monitoring of log files with is not accurate for long running processes that are using the Serilog logging framework, because Serilog often has a lock on the file even with shared: true

The Serilog config snippet I’m using: Log.Logger = new LoggerConfiguration() .MinimumLevel.Debug() .WriteTo.File(logFile, shared: true) .CreateLogger();