The Log.Information("Hello"); is not writing to the table. I have used the basic configuration here in the readme file and the sink created my table OK on first run. I am certain that my user has read/write permission.
I am expecting the Log.Information("Hello"); to add a row to the table.
Serilog.Debugging.SelfLog.Enable(msg => Debug.WriteLine(msg));
var logDB = #"data source=xxxxxx\SQLEXPRESS;initial catalog=Eng;integrated security=False;persist security info=True;user id=xxxx;password=xxxxxxxx";
var sinkOpts = new SinkOptions();
sinkOpts.TableName = "SL24AddInLogging";
sinkOpts.AutoCreateSqlTable = true;
var columnOpts = new ColumnOptions();
columnOpts.Store.Remove(StandardColumn.Properties);
columnOpts.Store.Add(StandardColumn.LogEvent);
columnOpts.LogEvent.DataLength = 2048;
columnOpts.PrimaryKey = columnOpts.TimeStamp;
columnOpts.TimeStamp.NonClusteredIndex = true;
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: logDB,
sinkOptions: sinkOpts,
columnOptions: columnOpts
).CreateLogger();
I must be doing something wrong. What?
There are a number of things you can do to troubleshoot issues in Serilog. Several are listed in this answer here on StackOverflow:
Serilog MSSQL Sink doesn't write logs to database
I found my issue. In the past when I have used Serilog I have used the static "Log.Information()" rather than my variable that is declared in my code when I create the logger. In this case my declared variable is also "log" - lower case.
Log.Information() - bad.
log.Information() - good.
Edit
In addition, in case you run into this. I have used the static version to have my logging available throughout the entire project. To define a logger and have it available you can use the following pattern:
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: logDB,
sinkOptions: sinkOpts,
columnOptions: columnOpts
).CreateLogger();
Log.Logger = log;
Related
Using Serilog with the MSSQL sink. I am logging OK when I write to the log after defining it in Main(). When I try to write to the log in Form1 form loading event handler it does not log.
The code in Program.cs Main() look like this and works.
var connectionString = #"Data Source=XXX\XXX; Initial Catalog=XXX; User ID=XXX; Password=XXX;";
var sinkOpts = new MSSqlServerSinkOptions();
sinkOpts.TableName = "Logs";
var columnOption = new ColumnOptions();
columnOption.Store.Remove(StandardColumn.MessageTemplate);
Log.Logger = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: connectionString,
sinkOptions: sinkOpts,
columnOptions: columnOption
).CreateLogger();
Log.Error("nujcsin");
Log.CloseAndFlush();
Code in Form1 loading handler looks like this. It does not log:
private void Form1_Load(object sender, EventArgs e)
{
List<ToolLocationItem> toolList = new List<ToolLocationItem>();
fastObjectListView1.ClearObjects();
fastObjectListView1.Refresh();
FillList();
Log.Information("Testing in Form1");
Log.CloseAndFlush();
}
I have tried replacing "WriteTo" with "AuditTo". I get nothing but my log entry in Main(). My Log.Information is not throwing any errors.
Why is Serilog not logging in Form1?
Edit
Same behaviour when using the file sink. Serilog logs when the logging statement is in the Main procedure but not elsewhere. It seems to be something that Serilog doesn't like rather than the sink.
You have Log.CloseAndFlush() in the code shortly after you initialize your logger. Like the documentation points out, this should be called only once right before the application exits.
Log.CloseAndFlush() will give the sinks a chance to wrap up what they were logging (some sinks are asynchronous) and then kill the logger, so any events logged after that will be lost. It disposes of the logger. So if you call that too soon, you're killing logging in the rest of your app.
You might think that putting it in a variable and then assigning it to the static logger was the solution, but you're misunderstanding what's going on. You haven't shown exactly what you did, but let's say you did this...
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: connectionString,
sinkOptions: sinkOpts,
columnOptions: columnOption
).CreateLogger();
Log.CloseAndFlush();
Log.Logger = log;
Now you've created a logger, assigned it to a local variable, closed and flushed (destroy/disposed) of the original static logger (there's a default implementation there that does nothing) then assigned the logger from your local variable to be the static logger. The key point is that all of this wouldn't be necessary if you closed and flushed in the proper place in the code, which is right before the program exits.
Wow. A new day and a fresh look.
What I did wrong is the following:
I needed to define the logger like this:
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: connectionString,
sinkOptions: sinkOpts,
columnOptions: columnOption
).CreateLogger();
and then:
Log.Logger = log;
If I defined my logger like this it did not seem to work outside the Main().
Log.Logger = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: connectionString,
sinkOptions: sinkOpts,
columnOptions: columnOption
).CreateLogger();
We are trying to load test our infrastructure of logstash/elastic. Since the actual logs are generated by a software that uses hardware, we are unable to simulate it at scale.
I am wondering if we can store the logs using file sink and later write a program that reads the log files and send data through the actual sink. Since, we are trying different setup, it would be great if we can swap different sinks for testing. Say http sink and elastic sink.
I thought of reading the json file one line at a time and then invoking Write method on the Logger. However I am not sure how to get the properties array from the json. Also, it would be great to hear if there are better alternatives in Serilog world for my needs.
Example parsing
var events= File.ReadAllLines(#"C:\20210520.json")
.Select(line => JsonConvert.DeserializeObject<dynamic>(line));
foreach (var o in objects)
{
DateTime timeStamp = o.Timestamp;
LogEventLevel level = o.Level;
string messageTemplate = o.MessageTemplate;
string exception = o.Exception;
var properties = (o.Properties as JObject);
List<object> parameters = new List<object>();
foreach (var property in properties)
{
if(messageTemplate.Contains(property.Key))
parameters.Add(property.Value.ToString());
}
logInstance.Write(level, messageTemplate, parameters.ToArray());
count++;
}
Example Json Event written to the file
{"Timestamp":"2021-05-20T13:15:49.5565372+10:00","Level":"Information","MessageTemplate":"Text dialog with {Title} and {Message} displayed, user selected {Selected}","Properties":{"Title":"Unload Device from Test","Message":"Please unload the tested device from test jig","Selected":"Methods.Option","SinkRepository":null,"SourceRepository":null,"TX":"TX2937-002 ","Host":"Host1","Session":"Host1-2021.05.20 13.12.44","Seq":87321,"ThreadId":3}}
UPDATE
Though this works for simple events,
it is not able to handle Context properties (there is a work around though using ForContext),
also it forces all the properties to be of type string and
not to mention that destucturing (#property) is not handled properly
If you can change the JSON format to Serilog.Formatting.Compact's CLEF format, then you can use Serilog.Formatting.Compact.Reader for this.
In the source app:
// dotnet add package Serilog.Formatting.Compact
Log.Logger = new LoggerConfiguration()
.WriteTo.File(new CompactJsonFormatter(), "./logs/myapp.clef")
.CreateLogger();
In the load tester:
// dotnet add package Serilog.Formatting.Compact.Reader
using (var target = new LoggerConfiguration()
.MinimumLevel.Verbose()
.WriteTo.Console()
.CreateLogger())
{
using (var file = File.OpenText("./logs/myapp.clef"))
{
var reader = new LogEventReader(file);
while (reader.TryRead(out var evt))
target.Write(evt);
}
}
Be aware though that load testing results won't be accurate for many sinks if you use repeated timestamps. You should consider re-mapping the events you read in to use current timestamps.
E.g. once you've loaded up evt:
var current = new LogEvent(DateTimeOffset.Now,
evt.Level,
evt.Exception,
evt.MessageTemplate,
evt.Properties);
target.Write(current);
This is my default Serilog configuration
SeriLogLevelSwitch.MinimumLevel = LogEventLevel.Information;
Log.Logger = new LoggerConfiguration()
.MinimumLevel.ControlledBy(SeriLogLevelSwitch)
.MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
.MinimumLevel.Override("Microsoft.Hosting.Lifetime", LogEventLevel.Information)
.Enrich.FromLogContext()
....
How can i change the loglevel to Debug for a specific namespace at runtime when the default is Information?
Each of your MinimumLevel.Override can have its own LoggingLevelSwitch, which allows you to control the log level for each particular override at run-time.
Create individual LoggingLevelSwitch for each override that you intend to modify whilst the app is running, and store these instances in a place that you can access from other parts of your application, which will allow you to change the MinimumLevel of these LoggingLevelSwitch(es).
e.g.
public class LoggingLevelSwitches
{
// Logging level switch that will be used for the "Microsoft" namespace
public static readonly LoggingLevelSwitch MicrosoftLevelSwitch
= new LoggingLevelSwitch(LogEventLevel.Warning);
// Logging level switch that will be used for the "Microsoft.Hosting.Lifetime" namespace
public static readonly LoggingLevelSwitch MicrosoftHostingLifetimeLevelSwitch
= new LoggingLevelSwitch(LogEventLevel.Information);
}
Configure your Serilog logging pipeline to use these LoggingLevelSwitch instances:
static void Main(string[] args)
{
Log.Logger = new LoggerConfiguration()
.MinimumLevel.Override("Microsoft", LoggingLevelSwitches.MicrosoftLevelSwitch)
.MinimumLevel.Override("Microsoft.Hosting.Lifetime",
LoggingLevelSwitches.MicrosoftHostingLifetimeLevelSwitch)
.Enrich.FromLogContext()
.CreateLogger();
// ...
}
Then somewhere in your application, for example, in the code that handles your application configuration that can be changed at run-time, update the LoggingLevelSwitch instance(s) to the new LogEventLevel that you want:
public class AppSettings
{
void ChangeLoggingEventLevel()
{
LoggingLevelSwitches.MicrosoftHostingLifetimeLevelSwitch
.MinimumLevel = LogEventLevel.Error;
LoggingLevelSwitches.MicrosoftHostingLifetimeLevelSwitch
.MinimumLevel = LogEventLevel.Warning;
// ...
}
}
As you can see, the LogEventLevel is controlled by the LoggingLevelSwitch instances, so it's up to you to decide where in your application (and how) these instances will be modified, to affect the logging pipeline.
The example above I'm assuming you have a screen (or API) in your application that a user would be able to configure the logging levels.
If you don't have that, then another approach is to have a background thread that periodically checks a configuration file, an environment variable, or query a database, etc. to determine what these logging levels should be.
If you're using a .NET Core Host, you can use the Options pattern which can handle the refresh of the configuration for you, and allow you to execute code when the configuration changes (where you'd change the MinimumLevel of your LoggingLevelSwitch(es) you have.
You can use an environment variable paired with another MinimumLevel.Override to change the loglevel to Debug for a specific namespace at runtime like so:
using System;
...
SeriLogLevelSwitch.MinimumLevel = LogEventLevel.Information;
Log.Logger = new LoggerConfiguration()
.MinimumLevel.ControlledBy(SeriLogLevelSwitch)
.MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
.MinimumLevel.Override("Microsoft.Hosting.Lifetime", LogEventLevel.Information)
.MinimumLevel.Override(Environment.GetEnvironmentVariable("SPECIFIC_NAMESPACE"), LogEventLevel.Debug)
.Enrich.FromLogContext()
....
Then, ensure the environment variable SPECIFIC_NAMESPACE is accessible by your application at runtime. Note that "namespace" is synonymous with "source context prefix"
Environment.GetEnvironmentVariable
this is my serilog configuration :
Log.Logger = new LoggerConfiguration()
.WriteTo.RollingFile(System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory,
#"Logs\log-{Date}.txt"))
.MinimumLevel.ControlledBy(LogLevelSwitch)
.CreateLogger();
i'm logging like this :
var log = Serilog.Log.ForContext<SomeClassName>();
log.Information("some log text");
My question :
I need a modification in my configuration to create separate logs for each SourceContext.
I need log files somthing like Logs\log-{Date}-{SourceContext}.txt
thanks pros...
One way to implement this is to create your own ILogEventSink implementation (the interface is very simple) that internally dispatches to one of several RollingFileSinks based on the SourceContext property of the LogEvent.
To configure it (let's say you call your sink SourceRollingFileSink) you can use WriteTo.Sink():
Log.Logger = new LoggerConfiguration()
.WriteTo.Sink(new SourceRollingFileSink())
.CreateLogger();
There's no out-of-the-box implementation so some work is required, but it should not be complicated. Be aware that implementations of ILogEventSink need to be thread-safe.
I want to write Serilog Warning events to a .NET collection so they can be included in a report to the user. How do I configure the static Log.Logger to write to something like a static List<string<> ?
I saw the Rx Observer in the list of provided sinks, this was the only one that seemed to readily make .NET objects available or is there an obvious alternative that I missed?
Alternatively, is this a dumb way to do it - is there a better way to collect just Warning events to massage into a user-facing report?
class CollectionSink : ILogEventSink {
public ICollection<LogEvent> Events { get; } = new ConcurrentBag<LogEvent>();
public void Emit(LogEvent le) {
Events.Add(le);
}
}
var col = new CollectionSink();
Log.Logger = new LoggerConfiguration()
.WriteTo.Sink(col, LogEventLevel.Warning)
.CreateLogger();
// read col.Events....
Not sure this one will typecheck but this is essentially how I've done it a few times.
I found the following implementations useful as references:
CollectionSink from the Serilog Timings tests
InMemorySink from Serilog.Sinks.InMemory