A Serilog sink that writes events to Microsoft SQL Server. This sink will write the log event data to a table and can optionally also store the properties inside an XML or JSON column so they can be queried. Important properties can also be written to their own separate columns.
Package - Serilog.Sinks.MSSqlServer | Minimum Platforms - .NET Framework 4.5.2, .NET Core 2.0, .NET Standard 2.0
- Sink Configuration Options
- Audit Sink Configuration
- Table Definition
- ColumnOptions Object
- SqlColumn Objects
- Standard Columns
- Custom Property Columns
- External Configuration Syntax
- Troubleshooting
- Querying Property Data
- Deprecated Features
The sink can be configured completely through code, by using configuration files (or other types of configuration providers), a combination of both, or by using the various Serilog configuration packages. There are two configuration considerations: configuring the sink itself, and configuring the table used by the sink. The sink is configured with a typical Serilog WriteTo
configuration method (or AuditTo
, or similar variations). The table is configured with an optional ColumnOptions
object passed to the configuration method.
All sink configuration methods accept the following arguments, though not necessarily in this order. Use of named arguments is strongly recommended. Some platform targets have additional arguments.
connectionString
schemaName
tableName
autoCreateSqlTable
columnOptions
restrictedToMinimumLevel
batchPostingLimit
period
formatProvider
At minimum, connectionString
and tableName
are required. If you are using an external configuration source such as an XML file or JSON file, you can use a named connection string instead of providing the full "raw" connection string.
If schemaName
is omitted, the default is dbo
.
If autoCreateSqlTable
is true
, the sink will create the table if a table by that name doesn't exist. It will also create the schema if no schema by that name exists. The account connecting to SQL Server will need adequate permissions to create a table (see the Permissions section of the Table Definition topic).
Table configuration with the optional ColumnOptions
object is a lengthy subject discussed in the ColumnOptions Object topic and other related topics.
Like other sinks, restrictedToMinimumLevel
controls the LogEventLevel
messages that are processed by this sink.
This is a "periodic batching sink." The sink will queue a certain number of log events before they're actually written to SQL Server as a bulk insert operation. There is also a timeout period so that the batch is always written even if it has not been filled. By default, the batch size is 50 rows and the timeout is 5 seconds. You can change these through by setting the batchPostingLimit
and period
arguments.
Consider increasing the batch size in high-volume logging environments. In one test of a loop writing a single log entry, the default batch size averaged about 14,000 rows per second. Increasing the batch size to 1000 rows increased average write speed to nearly 43,000 rows per second. However, you should also consider the risk-factor. If the client or server crashes, or if the connection goes down, you may lose an entire batch of log entries. You can mitigate this by reducing the timeout. Run performance tests to find the optimal batch size for your production log table definition and log event content, network setup, and server configuration.
Refer to the Serilog Wiki's explanation of Format Providers for details about the formatProvider
arguments.
These additional arguments are accepted when the sink is configured from a library or application that supports the .NET Standard-style Microsoft.Extensions.Configuration packages. They are optional.
appConfiguration
columnOptionsSection
The full configuration root provided to the appConfiguration
argument is only required if you are using a named connection string. The sink needs access to the entire configuration object so that it can locate and read the ConnectionStrings
section.
If you define the log event table through external configuration, you must provide a reference to the columnOptionsSection
via the argument by the same name.
Because of the way external configuration has been implemented in various .NET frameworks, you should be aware of how your target framework impacts which external configuration options are available. System.Configuration refers to the use of XML-based app.config
or web.config
files, and Microsoft.Extensions.Configuration (M.E.C) collectively refers to all of the extensions packages that were created as part of .NET Standard and the various compliant frameworks. M.E.C is commonly referred to as "JSON configuration" although the packages support many other configuration sources including environment variables, command lines, Azure Key Vault, XML, and more.
Your Framework | TFM | Project Types | External Configuration |
---|---|---|---|
.NET Framework 4.5.2 | net452 |
app or library | System.Configuration |
.NET Framework 4.6.1+ | net461 |
app or library | System.Configuration |
.NET Framework 4.6.1+ | net461 |
app or library | Microsoft.Extensions.Configuration |
.NET Standard 2.0 | netstandard2.0 |
library only | Microsoft.Extensions.Configuration |
.NET Core 2.0+ | netcoreapp2.0 |
app or library | System.Configuration |
.NET Core 2.0+ | netcoreapp2.0 |
app or library | Microsoft.Extensions.Configuration |
Support for .NET Framework 4.5.2 is tied to the Windows 8.1 lifecycle with support scheduled to end in January 2023.
Although it's possible to use both XML and M.E.C configuration with certain frameworks, this is not supported, unintended consequences are possible, and a warning will be emitted to SelfLog
. If you actually require multiple configuration sources, the M.E.C builder-pattern is designed to support this, and your syntax will be consistent across configuration sources.
All sink features are configurable from code. Here is a typical example that works the same way for any .NET target. This example configures the sink itself as well as table features.
var logDB = @"Server=...";
var logTable = "Logs";
var options = new ColumnOptions();
options.Store.Remove(StandardColumn.Properties);
options.Store.Add(StandardColumn.LogEvent);
options.LogEvent.DataLength = 2048;
options.PrimaryKey = options.TimeStamp;
options.TimeStamp.NonClusteredIndex = true;
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: logDB,
tableName: logTable,
columnOptions: opts
).CreateLogger();
Projects can build (or inject) a configuration object using Microsoft.Extensions.Configuration and pass it to the sink's configuration method. If provided, the settings of a ColumnOptions
object created in code are treated as a baseline which is then updated from the external configuration data. See the External Configuration Syntax topic for details.
var appSettings = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json")
.Build();
var logDB = @"Server=...";
var logTable = "Logs";
var opts = new ColumnOptions();
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(
connectionString: logDB,
tableName: logTable,
columnOptions: opts,
appConfiguration: appSettings
).CreateLogger();
.CreateLogger();
Projects can load ColumnOptions
table configuration from an XML configuration file such as app.config
or web.config
. The sink configuration method automatically checks ConfigurationManager
, so there is no code to show, and no additional packages are required. See the External Configuration Syntax topic for details.
Requires configuration package version 3.0.0 or newer.
.NET Standard projects can call ReadFrom.Configuration()
to configure Serilog using the Serilog.Settings.Configuration package. This will apply configuration arguments from all application configuration sources (not only appsettings.json
as shown here, but any other valid IConfiguration
source). This package can configure the sink itsef as well as ColumnOptions
table features. See the External Configuration Syntax topic for details.
Projects can configure the sink from XML configuration by calling ReadFrom.AppSettings()
using the Serilog.Settings.AppSettings package. This will apply configuration arguments from the project's app.config
or web.config
file. This is independent of configuring ColumnOptions
from external XML files. See the External Configuration Syntax topic for details.
A Serilog audit sink writes log events which are of such importance that they must succeed, and that verification of a successful write is more important than write performance. Unlike the regular sink, an audit sink does not fail silently -- it can throw exceptions. You should wrap audit logging output in a try/catch
block. The usual example is bank account withdrawal events -- a bank would certainly not want to allow a failure to record those transactions to fail silently.
The constructor accepts most of the same arguments, and like other Serilog audit sinks, you configure one by using AuditTo
instead of WriteTo
.
connectionString
schemaName
tableName
autoCreateSqlTable
columnOptions
formatProvider
The restrictedToMinimumLevel
parameter is not available because all events written to an audit sink are required to succeed.
The batchPostingLimit
and period
parameters are not available because the audit sink writes log events immediately.
For M.E.C-compatible projects, appConfiguration
and columnOptionsSection
arguments are also provided, just as they are with the non-audit configuration extensions.
If you don't use the auto-table-creation feature, you'll need to create a log event table in your database. In particular, give careful consideration to whether you need the Id
column (options and performance impacts are discussed in the Standard Columns topic). The table definition shown below reflects the default configuration using auto-table-creation without changing any sink options. Many other variations are possible. Refer to the ColumnOptions Object topic to understand how the various configuration features relate to the table definition.
IMPORTANT: If you create your log event table ahead of time, the sink configuration must exactly match that table, or errors are likely to occur.
CREATE TABLE [Logs] (
[Id] int IDENTITY(1,1) NOT NULL,
[Message] nvarchar(max) NULL,
[MessageTemplate] nvarchar(max) NULL,
[Level] nvarchar(128) NULL,
[TimeStamp] datetime NOT NULL,
[Exception] nvarchar(max) NULL,
[Properties] nvarchar(max) NULL
CONSTRAINT [PK_Logs] PRIMARY KEY CLUSTERED ([Id] ASC)
);
At a minimum, writing log entries requires SELECT and INSERT permissions for the log table. (SELECT is required because the sink's batching behavior uses bulk inserts which reads the schema before the write operations begin).
SQL permissions are a very complex subject. Here is an example of one possible solution (valid for SQL 2012 or later):
CREATE ROLE [SerilogAutoCreate];
GRANT SELECT ON sys.tables TO [SerilogAutoCreate];
GRANT SELECT ON sys.schemas TO [SerilogAutoCreate];
GRANT ALTER ON SCHEMA::[dbo] TO [SerilogAutoCreate]
GRANT CREATE TABLE ON DATABASE::[SerilogTest] TO [SerilogAutoCreate];
CREATE ROLE [SerilogWriter];
GRANT SELECT TO [SerilogWriter];
GRANT INSERT TO [SerilogWriter];
CREATE LOGIN [Serilog] WITH PASSWORD = 'password';
CREATE USER [Serilog] FOR LOGIN [Serilog] WITH DEFAULT_SCHEMA = dbo;
GRANT CONNECT TO [Serilog];
ALTER ROLE [SerilogAutoCreate] ADD MEMBER [Serilog];
ALTER ROLE [SerilogWriter] ADD MEMBER [Serilog];
This creates a SQL login named Serilog
, a database user named Serilog
, and assigned to that user are the roles SerilogAutoCreate
and SerilogWriter
. As the name suggests, the SerilogAutoCreate
role is not needed if you create the database ahead of time, which is the recommended course of action if you're concerned about security at this level.
Ideally the SerilogWriter
role would be restricted to the log table only, and that table has to already exist to use table-specific GRANT
statements, so that's another reason that you probably don't want to use auto-create if you're concerned about log security. Table-level restrictions would look like this (assuming you name your log table SecuredLog
, of course):
GRANT SELECT ON [dbo].[SecuredLog] TO [SerilogWriter];
GRANT SELECT ON [dbo].[SecuredLog] TO [SerilogWriter];
There are many possible variations. For example, you could also create a logging-specific schema and restrict access that way.
Features of the log table are defined by changing properties on a ColumnOptions
object:
Store
PrimaryKey
ClusteredColumnstoreIndex
DisableTriggers
AdditionalColumns
This is a list of columns that have special handling when a log event is being written. These are explained in the Standard Columns topic. Only the Standard Columns which are in the log table should be present in the Store
collection. This is a List<>
of StandardColumn
enumeration members, so you can simply Add
or Remove
columns to change the list. The order of appearance does not matter. The ColumnOptions
object also has a property for each individual Standard Column providing access to column-specific settings. The properties match the Standard Column names (Id
, Message
, etc.) These are discussed in the documentation for each Standard Column.
By default, the Id
Standard Column is the table's primary key. You can set this property to any other column (either Standard Columns or custom columns you define; see the Custom Property Columns topic). SQL Server requires primary key indexes to always be NOT NULL
so the column-level AllowNull
property will be overridden if set to true
.
The primary key is optional; set this property to null
to create a heap table with no primary key.
NOTE: If you do not set the NonClusteredIndex
property on the primary key column to true
, the primary key constraint will be created as a clustered index. Clustered indexing is the default for backwards-compatibility reasons, but generally speaking this is not the best option for logging purposes (applications rarely emit fully unique properties, and using the unique auto-incrementing Id
column as a primary key isn't particularly useful for query purposes).
Setting this to true
changes the table to the clustered columnstore index (CCI) format. A complete discussion of CCI is beyond the scope of this documentation, but generally it uses high compression to dramatically improve search speeds. It is not compatible with a table primary key or a non-columnstore clustered index, and supporting (max)
length character-data columns requires SQL 2017 or newer.
Disabling triggers can significantly improve batch-write performance.
This is a Collection<>
of SqlColumn
objects that you create to define custom columns in the log event table. Refer to the Custom Property Columns topic for more information.
Each Standard Column in the ColumnOptions.Store
list and any custom columns you add to the AdditionalColumns
collection are SqlColumn
objects with the following properties:
ColumnName
DataType
AllowNull
DataLength
NonClusteredIndex
Any valid SQL column name can be used. Standard Columns have default names assigned but these can be changed without affecting their special handling.
This property can be set to nearly any value in the System.Data.SqlDbType
enumeration. Unlike previous versions of this sink, SQL column types are fully supported end-to-end, including auto-table-creation. Earlier limitations imposed by the use of the .NET DataColumn
object no longer apply. Most of the Standard Columns only support a limited subset of the SQL column types (and often just one type). Some of the special-case SQL column types are excluded such as timestamp
and udt
, and deprecated types like text
and image
are excluded. These are the supported SQL column data types:
bigint
bit
char
date
datetime
datetime2
datetimeoffset
decimal
float
int
money
nchar
nvarchar
real
smalldatetime
smallint
smallmoney
time
tinyint
uniqueidentifier
varchar
xml
Numeric types use the default precision and scale. For numeric types, you are responsible for ensuring the values you write do not exceed the min/max values of the underlying SQL column data types. For example, the SQL decimal
type defaults to 18-digit precision (and scale 0) meaning the maximum value is 1018-1, or 999,999,999,999,999,999, whereas the .NET decimal
type has a much higher maximum value of 79,228,162,514,264,337,593,543,950,335.
Determines whether or not the column can store SQL NULL
values. Some of the other features like PrimaryKey
have related restrictions, and some of the Standard Columns impose restrictions (for example, the Id
column never allows nulls).
For character-data and binary columns, this defines the column size (or maximum size if variable-length). The value -1 indicates (max)
length and is the property's default. If the column data type doesn't support this, the setting is ignored. Note that clustered columnstore indexing is incompatible with (max)
length columns prior to SQL 2017.
Supported SQL column data types that use this property:
char
nchar
nvarchar
varchar
Any individual column can be defined as a non-clustered index, including the table primary key. Use this with caution, indexing carries a relatively high write-throughput penalty. One way to mitigate this is to keep non-clustered indexes offline and use batch reindexing on a scheduled basis.
By default (and consistent with the SQL DDL to create a table shown earlier) these columns are included in a new ColumnOptions.Store
list:
StandardColumn.Id
StandardColumn.Message
StandardColumn.MessageTemplate
StandardColumn.Level
StandardColumn.TimeStamp
StandardColumn.Exception
StandardColumn.Properties
There is one additional Standard Column which is not included by default (for backwards-compatibility reasons):
StandardColumn.LogEvent
You can change this list as long as the underlying table definition is consistent:
// we don't need XML data
columnOptions.Store.Remove(StandardColumn.Properties);
// we do want JSON data
columnOptions.Store.Add(StandardColumn.LogEvent);
In addition to any special properties described below, each Standard Column also has the usual column properties like ColumnName
as described in the topic SqlColumn Objects.
The Id
column is an optional table identity column. It defaults to the int
data type but can also be configured as bigint
. The AllowNull
property is always false
. If it is included in the table, it must be an auto-incrementing unique identity column and is automatically configured and auto-created as such.
Previous versions of this sink assumed the Id
column was always present as an int
identity primary key with a clustered index. Other configurations are possible and probably preferable, however this is still the default for backwards-compatibility reasons. Carefully consider your anticipated logging volume and query requirements. The default setting is not ideal in real-world scenarios since a clustered index is primarily of use when the key is used for sorting or range searches. This is rarely the case for the Id
column.
No Id column: If you eliminate the column completely, the log table is stored as an unorded heap (as long as you don't define a different clustered primary key, which is not recommended). This is the ideal write-speed scenario for logging, however any non-clustered indexes you add will slightly degrade write performance.
Non-clustered primary key: You can also retain the column as an identity primary key, but using a non-clustered index. The log is still stored as an unordered heap, but writing a non-clustered index is slightly faster. Non-clustered indexes on other columns will reference the Id primary key. However, read performance will be slightly degraded since it requires two reads (searching the non-clustered index, then dereferencing the heap row from the Id).
BigInt data type: For very large log tables, if you absolutely require an identity column, you may wish to define the Id
as the SQL bigint
datatype. This 8-byte integer (equivalent to a c# long
integer) will permit a maximum identity value of 9,223,372,036,854,775,807. This will slightly degrade both read and write performance.
This column stores the formatted output (property placeholders are replaced with property values). It defaults to nvarchar(max)
. The DataType
property can only be set to character-storage types.
This column stores the log event message with the property placeholders. It defaults to nvarchar(max)
. The DataType
property can only be set to character-storage types.
This column stores the event level (Error, Information, etc.). For backwards-compatibility reasons it defaults to a length of 128 characters, but 12 characters is recommended. Alternately, the StoreAsEnum
property can be set to true
which causes the underlying level enum integer value to be stored as a SQL tinyint
column. The DataType
property can only be set to nvarchar
or tinyint
. Setting the DataType
to tinyint
is identical to setting StoreAsEnum
to true
.
This column stores the time the log event was sent to Serilog as a SQL datetime
type. While this may appear to be a good candidate as a clustered primary key, even relatively low-volume logging can emit identical timestamps forcing SQL Server to add a "uniqueifier" value behind the scenes (effectively an auto-incrementing identity-like integer). For frequent timestamp range-searching and sorting, a non-clustered index is better.
When the ConvertToUtc
property is set to true
, the time stamp is adjusted to the UTC standard. Normally the time stamp value reflects the local time of the machine issuing the log event, including the current timezone information. For example, if the event is written at 07:00 Eastern time, the Eastern timezone is +4:00 relative to UTC, so after UTC conversion the time stamp will be 11:00. Offset is stored as +0:00 but this is not the GMT time zone because UTC does not use offsets (by definition). To state this another way, the timezone is discarded and unrecoverable. UTC is a representation of the date and time exclusive of timezone information. This makes it easy to reference time stamps written from different or changing timezones.
When an exception is logged as part of the log event, the exception message is stored here automatically. The DataType
must be nvarchar
.
This column stores log event property values as XML. Typically you will use either this column or the JSON-based LogEvent
column, but not both.
The DataType
defaults to nvarchar
and it is strongly recommended that this not be changed, but the SQL xml
type is also supported. Using the xml
type causes SQL server to convert the string data to a storage-efficent representation which can be searched much more quickly, but there is a measurable CPU-overhead cost. Test carefully with realistic workloads before committing to the xml
data type.
The ExcludeAdditionalProperties
setting is described in the Custom Property Columns topic.
Names of elements can be controlled by the RootElementName
, PropertyElementName
, ItemElementName
, DictionaryElementName
, SequenceElementName
, StructureElementName
and UsePropertyKeyAsElementName
options.
The UsePropertyKeyAsElementName
option, if set to true
, will use the property key as the element name instead of "property" for the name with the key as an attribute.
If OmitDictionaryContainerElement
, OmitSequenceContainerElement
or OmitStructureContainerElement
are set then the "dictionary", "sequence" or "structure" container elements will be omitted and only child elements are included.
If OmitElementIfEmpty
is set then if a property is empty, it will not be serialized.
This column stores log event property values as JSON. Typically you will use either this column or the XML-based Properties
column, but not both. This column's DataType
must always be nvarchar
.
The ExcludeAddtionalProperties
and ExcludeStandardColumns
properties are described in the Custom Property Columns topic.
By default, any log event properties you include in your log statements will be saved to the XML Properties
column or the JSON LogEvent
column. But they can also be stored in their own individual columns via the AdditionalColumns
collection. This adds overhead to write operations but is very useful for frequently-queried properties. Only ColumnName
is required; the default configuration is varchar(max)
.
var columnOptions = new ColumnOptions
{
AdditionalColumns = new Collection<SqlColumn>
{
new SqlColumn
{ColumnName = "UserName", DataType = SqlDbType.NVarChar, DataLength = 64},
new SqlColumn
{ColumnName = "UserId", DataType = SqlDbType.BigInt, NonClusteredIndex = true},
new SqlColumn
{ColumnName = "RequestUri", DataType = SqlDbType.NVarChar, DataLength = -1, AllowNull = false},
}
};
var log = new LoggerConfiguration()
.WriteTo.MSSqlServer(@"Server=...", "Logs", columnOptions: columnOptions)
.CreateLogger();
In this example, when a log event contains any of the properties UserName
, UserId
, and RequestUri
, the property values would be written to the corresponding columns. The property names must match exactly (case-insensitive).
Unlike previous versions of the sink, Standard Column names are not reserved. If you remove the Id
Standard Column from the ColumnOptions.Store
list, you are free to create a new custom column called Id
which the sink will treat like any other custom column fully under your control.
Note the use of the SqlDbType
enumerations for specifying DataType
. Unlike previous versions of the sink, .NET System
data types and DataColumn
objects are no longer used for custom column definition.
By default, properties matching a custom column will still be included in the data saved to the XML Properties
or JSON LogEvent
column. This is consistent with the idea behind structured logging, and makes it easier to convert the log data to another document-data storage platform later, if desired.
However, the properties being saved in their own columns can be excluded from these catch-all columns. Use the columnOptions.Properties.ExcludeAdditionalProperties
parameter to exclude the redundant properties from the Properties
XML column, or columnOptions.LogEvent.ExcludeAdditionalProperties
if you're using the JSON LogEvent
column.
Standard Columns are always excluded from the XML Properties
column but Standard Columns are included in the JSON data for backwards-compatibility reasons. They can be excluded from the JSON LogEvent
column with columnOptions.LogEvent.ExcludeStandardColumns
.
Projects targeting frameworks which are compatible with System.Configuration automatically have support for XML-based configuration (either app.config
or web.config
) of a ColumnOptions
table definition, and the Serilog.Settings.AppSettings package adds XML-based configuration of sink arguments.
Projects targeting frameworks which are compatible with Microsoft.Extensions.Configuration can apply configuration-driven sink setup and ColumnOptions
settings using the Serilog.Settings.Configuration package or by supplying the appropriate arguments through code.
All properties of the ColumnOptions
class are configurable except the Properties.PropertyFilter
predicate expression, and all elements and lists shown are optional. In most cases configuration keynames match the class property names, but there are some exceptions. For example, because PrimaryKey
is a SqlColumn
object reference when configured through code, external configuration uses a primaryKeyColumnName
setting to identify the primary key by name.
Custom columns and the stand-alone Standard Column entries all support the same general column properties (ColumnName
, DataType
, etc) listed in the SqlColumn Objects topic. The following sections documenting configuration syntax omit many of these properties for brevity.
If you combine external configuration with configuration through code, external configuration changes will be applied in addition to a ColumnOptions
object you provide through code (external configuration "overwrites" properties defined in configuration, but properties only defined through code are preserved).
IMPORTANT: Some of the following examples do not reflect real-world configurations that can be copy-pasted as-is. Some settings or properties shown are mutually exclusive and are listed below for documentation purposes only.
Keys and values are not case-sensitive. This is an example of configuring the sink arguments.
{
"Serilog": {
"Using": ["Serilog.Sinks.MSSqlServer"],
"MinimumLevel": "Debug",
"WriteTo": [
{ "Name": "MSSqlServer",
"Args": {
"connectionString": "NamedConnectionString",
"schemaName": "EventLogging",
"tableName": "Logs",
"autoCreateSqlTable": true,
"restrictedToMinimumLevel": "Warning",
"batchPostingLimit": 1000,
"period": "0.00:00:30",
"columnOptionsSection": { . . . }
}
}
]
}
}
As the name suggests, columnOptionSection
is an entire configuration section in its own right. The AdditionalColumns
collection can also be populated from a key named customColumns
(not shown here) for backwards-compatibility reasons.
"columnOptionsSection": {
"disableTriggers": true,
"clusteredColumnstoreIndex": false,
"primaryKeyColumnName": "Id",
"addStandardColumns": [ "LogEvent" ],
"removeStandardColumns": [ "MessageTemplate", "Properties" ],
"additionalColumns": [
{ "ColumnName": "EventType", "DataType": "int", "AllowNull": false },
{ "ColumnName": "Release", "DataType": "varchar", "DataLength": 32 },
{ "ColumnName": "All_SqlColumn_Defaults",
"DataType": "varchar",
"AllowNull": true,
"DataLength": -1,
"NonClusteredIndex": false
}
],
"id": { "nonClusteredIndex": true },
"level": { "columnName": "Severity", "storeAsEnum": false },
"properties": {
"columnName": "Properties",
"excludeAdditionalProperties": true,
"dictionaryElementName": "dict",
"itemElementName": "item",
"omitDictionaryContainerElement": false,
"omitSequenceContainerElement": false,
"omitStructureContainerElement": false,
"omitElementIfEmpty": true,
"propertyElementName": "prop",
"rootElementName": "root",
"sequenceElementName": "seq",
"structureElementName": "struct",
"usePropertyKeyAsElementName": false
},
"timeStamp": { "columnName": "Timestamp", "convertToUtc": true },
"logEvent": {
"excludeAdditionalProperties": true,
"excludeStandardColumns": true
},
"message": { "columnName": "Msg" },
"exception": { "columnName": "Ex" },
"messageTemplate": { "columnName": "Template" }
}
Keys and values are case-sensitive. Case must match exactly as shown below.
<configSections>
<section name="MSSqlServerSettingsSection"
type="Serilog.Configuration.MSSqlServerConfigurationSection, Serilog.Sinks.MSSqlServer"/>
</configSections>
<MSSqlServerSettingsSection DisableTriggers="false"
ClusteredColumnstoreIndex="false"
PrimaryKeyColumnName="Id">
<AddStandardColumns>
<add Name="LogEvent"/>
</AddStandardColumns>
<RemoveStandardColumns>
<remove Name="Properties"/>
</RemoveStandardColumns>
<Columns>
<add ColumnName="EventType" DataType="int"/>
<add ColumnName="Release"
DataType="varchar"
DataLength="64"
AllowNull="true"
NonClusteredIndex="false"/>
</Columns>
<Exception ColumnName="Ex" DataLength="512"/>
<Id NonClusteredIndex="true"/>
<Level ColumnName="Severity" StoreAsEnum="true"/>
<LogEvent ExcludeAdditionalProperties="true"
ExcludeStandardColumns="true"/>
<Message DataLength="1024"/>
<MessageTemplate DataLength="1536"/>
<Properties DataType="xml"
ExcludeAdditionalProperties="true"
DictionaryElementName="dict"
ItemElementName="item"
OmitDictionaryContainerElement="false"
OmitSequenceContainerElement="false"
OmitStructureContainerElement="false"
OmitElementIfEmpty="true"
PropertyElementName="prop"
RootElementName="root"
SequenceElementName="seq"
StructureElementName="struct"
UsePropertyKeyAsElementName="false"/>
<TimeStamp ConvertToUtc="true"/>
</MSSqlServerSettingsSection>
Refer to the Serilog.Settings.AppSettings package documentation for complete details about sink configuration. This is an example of setting some of the configuration parameters for this sink.
<add key="serilog:using:MSSqlServer" value="Serilog.Sinks.MSSqlServer" />
<add key="serilog:write-to:MSSqlServer.connectionString" value="EventLogDB"/>
<add key="serilog:write-to:MSSqlServer.tableName" value="Logs"/>
<add key="serilog:write-to:MSSqlServer.autoCreateSqlTable" value="true"/>
This is a relatively complex sink, and there are certain common problems which you should investigate before opening a new issue to ask for help. If you do open a new issue, please be sure to tell us all of the Serilog packages you are using and which versions, show us your real configuration code and any external configuration sources, and a simple example of code which reproduces the problem. If you're getting an error message, please include the exact message.
After configuration is complete, this sink runs through a number of checks to ensure consistency. Some configuration issues result in an exception, but others may only generate warnings through Serilog's SelfLog
feature. At runtime, exceptions are silently reported through SelfLog
. Refer to Debugging and Diagnostics in the main Serilog documentation to enable SelfLog
output.
Any Serilog application should always call Log.CloseAndFlush
before shutting down. This is especially important in sinks like this one. It is a "periodic batching sink" which means log event records are written in batches for performance reasons. Calling Log.CloseAndFlush
should guarantee any batch in memory will be written to the database (but read the Visual Studio note below). You may wish to put the Log.CloseAndFlush
call in a finally
block in console-driven apps where a Main
loop controls the overall startup and shutdown process. Refer to the Serilog.AspNetCore sample code for an example. More exotic scenarios like dependency injection may warrant hooking the ProcessExit
event when the logger is registered as a singleton:
AppDomain.CurrentDomain.ProcessExit += (s, e) => Log.CloseAndFlush();
When you exit an application running in debug mode under Visual Studio, normal shutdown processes may be interrupted. Visual Studio issues a nearly-instant process kill command when it decides you're done debugging. This is a particularly common problem with ASP.NET and ASP.NET Core applications, in which Visual Studio instantly terminates the application as soon as the browser is closed. Even finally
blocks usually fail to execute. If you aren't seeing your last few events written, try testing your application outside of Visual Studio.
If you're reading about a feature that doesn't seem to work, check whether you're reading the docs for the master
branch or the dev
branch -- most Serilog repositories are configured to use the dev
branch by default. If you see something interesting only described by the dev
branch documentation, you'll have to reference a dev
-versioned package. The repository automatically generates a new dev
package whenever code-related changes are merged.
Please check your NuGet references and confirm you are specifically referencing Serilog.Sinks.MSSqlServer. In the early days of .NET Core, there was a popular Core-specific fork of this sink, but the documentation and NuGet project URLs pointed here. Today the package is marked deprecated, but we continue to see some confusion around this.
Extracting and querying the property column directly can be helpful when looking for specific log sequences. SQL Server has query syntax supporting columns that store either XML or JSON data.
This capability requires SQL 2012 or newer. Given the following JSON properties:
{
"Properties": {
"Action": "GetUsers",
"Controller": "UserControler"
}
}
The following query will extract the Action
property and restrict the query based on the Controller
property using SQL Server's built-in JSON path support.
SELECT
[Message], [TimeStamp], [Exception],
JSON_VALUE(LogEvent, '$.Properties.Action') AS Action
FROM [Logs]
WHERE
JSON_VALUE(LogEvent, '$.Properties.Controller') = 'UserController'
Given the following XML properties:
<properties>
<property key="Action">GetUsers</property>
<property key="Controller">UserController</property>
</properties>
The following query will extract the Action
property and restrict the query based on the Controller
property using SQL Server's built-in XQuery support.
SELECT
[Message], [TimeStamp], [Exception],
[Properties].value('(//property[@key="Action"]/node())[1]', 'nvarchar(max)') AS Action
FROM [Logs]
WHERE
[Properties].value('(//property[@key="Controller"]/node())[1]', 'nvarchar(max)') = 'UserController'
Feature | Notes |
---|---|
AdditionalDataColumns |
Use the AdditionalColumns collection instead. Configuring the sink no longer relies upon .NET DataColumn objects or .NET System types. |
Id.BigInt |
Use Id.DataType = SqlDb.BigInt instead. (The BigInt property was only available in dev packages). |
Binary and VarBinary |
Due to the way Serilog represents property data internally, it isn't possible for the sink to access property data as a byte array, so the sink can't write to these column types. |
Most deprecated features are still available, but they are marked with the [Obsolete]
attribute (which results in a compiler warning in your project) and will be removed in a future release. You should switch to the replacement implementations as soon as possible. Where possible, internally these are converted to the replacement implementation so that they only exist at the configuration level.