Setting levels for logging, metrics, and tracing¶

You can set the threshold levels for log, trace, or metrics data captured in an event table.

For each type of telemetry data, you can do the following:

Set levels specific to each type of telemetry data.
Set system-wide levels for each that are in effect unless overridden.
Override system-wide levels by setting the level for a session or on specific objects (such as procedures and UDFs).

Levels are represented as both session parameters and object parameters.

Note

You can use handler code to override the log level you set with SQL (as described in this topic) when your handler is written in Python. For more information, see Overriding log threshold levels with Python.

Understanding logging, metrics, and tracing levels¶

Each type of telemetry data supports its own set of levels that are specific to its purpose. You can set these levels by using the parameter Snowflake provides for each. You can also set some levels using Snowsight, which represents the level parameters in a simplified way.

You can set each of these in the following ways:

At the account level.
At the database, schema, or other object level with SQL.
At the database or schema level using Snowsight.
At the session level.

Logging:

When you set a level, only data at that level and more severe levels are captured in an event table and visible in Snowsight. For example, setting the LOG_LEVEL parameter to WARN means that messages at the WARN, ERROR, and FATAL levels are captured in the event table.

Levels are determined by the LOG_LEVEL parameter.

Metrics:

You can currently have all metrics data captured or none.

Levels are determined by the METRIC_LEVEL parameter.

Tracing:

You can specify the scope of trace event data stored in the event table.

Levels are determined by the TRACE_LEVEL parameter.

Setting the level for the account¶

For each type of telemetry data, you can set the level on for the account. You can override this level at the object and session level as decribed in Understanding how Snowflake determines level in effect.

Verify that you have the needed privileges¶

To set levels for the account, you must use a role that is granted or inherits the privileges described below.

For more information about the privileges, see Access control privileges.

Level to modify	Parameter to set	Privileges needed
Log level	LOG_LEVEL	MODIFY LOG LEVEL on the account
Metric level	METRIC_LEVEL	MODIFY METRIC LEVEL on the account
Trace level	TRACE_LEVEL	MODIFY TRACE LEVEL on the account

Code in the following example grants privileges needed for someone using the central_log_admin role to set the log level for the account.

GRANT MODIFY LOG LEVEL ON ACCOUNT TO ROLE central_log_admin;

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Setting the level on the account in Snowsight¶

Note

Snowsight support for logging and tracing is a preview feature available to all accounts.

You can use Snowsight to set telemetry levels at the account level.

Verify that you have access to a role with privileges needed to set levels.
Sign in to Snowsight.
In the navigation menu, select Monitoring » Traces and Logs.
In the Traces & Logs page, select the Set Event Level.
For Set logging & tracing for, select Account.

Select the levels the telemetry data you want to adjust.

All Events	On to turn on collection for all kinds of telemetry data; Off to turn off collection for all kinds of data.
Traces	On to set trace data collection to `ALWAYS`; Off to set trace data collection to `OFF`. See TRACE_LEVEL for information about levels.
Logs	On to set log data collection to `INFO`. See LOG_LEVEL for information about levels.
Metrics	On to set trace data collection to `ALL`; Off to set trace data collection to `NONE`. See METRIC_LEVEL for information about levels.

Setting the level on the account with SQL¶

You can use SQL to set telemetry levels for the account.

To set a telemetry level on the account, do the following:

Verify that you have access to a role with privileges needed to set levels.
Use the ALTER ACCOUNT command to set the appropriate parameter, based on the telemetry data you want to collect.

For the list of levels that you can use, see Understanding logging, metrics, and tracing levels.

The following example sets the log level to ERROR for the account.
```
-- Set the log level on the account
ALTER ACCOUNT SET LOG_LEVEL = ERROR;
```
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Setting the level for an object¶

For each type of telemetry data, you can set the level on the following objects:

A stored procedure
A user-defined function (UDF) or a user-defined table function (UDTF)
A database or schema containing procedures and functions

Note

You can’t set the level on Streamlit objects. Instead, set the level on the database or schema containing the object.

Verify that you have the needed privileges¶

To set levels on an object, you must use a role that is granted or inherits the privileges described below.

For more information about privileges, see Access control privileges.

Level to modify	Parameter to set	Privileges needed
Log level	LOG_LEVEL	MODIFY LOG LEVEL on the account MODIFY on the object for which you want to set the level USAGE on the database or schema containing the procedure or UDF for which you want to set the level
Metric level	METRIC_LEVEL	MODIFY METRIC LEVEL on the account MODIFY on the object for which you want to set the level USAGE on the database or schema containing the procedure or UDF for which you want to set the level
Trace level	TRACE_LEVEL	MODIFY TRACE LEVEL on the account MODIFY on the object for which you want to set the level USAGE on the database or schema containing the procedure or UDF for which you want to set the level

Code in the following example grants privileges needed for someone using the central_log_admin role to set the log level for the db1 database.

GRANT MODIFY LOG LEVEL ON ACCOUNT TO ROLE central_log_admin;
GRANT MODIFY ON DATABASE db1 TO ROLE central_log_admin;

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Setting the level on a database or schema in Snowsight¶

Note

Snowsight support for logging and tracing is a preview feature available to all accounts.

You can use Snowsight to set telemetry levels. Before you begin, verify that you have access to a role with privileges needed to set levels.

Verify that you have access to a role with privileges needed to set levels.
Sign in to Snowsight.
In the navigation menu, select Monitoring » Traces and Logs.
In the Traces & Logs page, select the Set Event Level.
For Set logging & tracing for, select the database and, optionally, schema for which you’re setting levels.

Select the levels the telemetry data you want to adjust.

All Events	On to turn on collection for all kinds of telemetry data; Off to turn off collection for all kinds of data.
Traces	On to set trace data collection to `ALWAYS`; Off to set trace data collection to `OFF`. See TRACE_LEVEL for information about levels.
Logs	On to set log data collection to `INFO`. See LOG_LEVEL for information about levels.
Metrics	On to set trace data collection to `ALL`; Off to set trace data collection to `NONE`. See METRIC_LEVEL for information about levels.

Setting the level on a database, schema, or other object with SQL¶

You can use SQL to set levels for logging, metrics, and tracing.

To set the telemetry level on an object, do the following:

Verify that you have access to a role with privileges needed to set levels.
Use the ALTER <object> command to set the LOG_LEVEL parameter on the object.

For the list of levels that you can use, see Understanding logging, metrics, and tracing levels.

For example, to set the log level for a specific UDF, use ALTER FUNCTION to set the LOG_LEVEL parameter for that UDF. As another example, to set the default log level for all functions and procedures in a database, use ALTER DATABASE to set the LOG_LEVEL parameter on that database.

The following example sets the log level to ERROR for all functions and procedures in the database db. The example overrides this level to WARN for the UDF f1(int).
```
USE ROLE central_log_admin;

-- Set the log levels on a database and UDF.
ALTER DATABASE db1 SET LOG_LEVEL = ERROR;
ALTER FUNCTION f1(int) SET LOG_LEVEL = WARN;
```
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For details on how Snowflake determines the effective log level when the LOG LEVEL is set on different objects, see Understanding how Snowflake determines level in effect.

Setting the level for the current session¶

To set the level for calls to functions and procedures made in the current session:

Verify that you have the privilege to set the level on the session.

You must use a role that has been granted the following privileges, depending on the levels you’re setting:

Level to modify	Parameter to set	Privileges needed
Log level	LOG_LEVEL	MODIFY SESSION LOG LEVEL
Metric level	METRIC_LEVEL	MODIFY SESSION METRIC LEVEL
Trace level	TRACE_LEVEL	MODIFY SESSION TRACE LEVEL

For example, to grant the developer_debugging role the privilege to set the log levels for the current session, execute the following statement:

GRANT MODIFY SESSION LOG LEVEL ON ACCOUNT TO ROLE developer_debugging;

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Use the ALTER SESSION command to set the LOG_LEVEL parameter for the current session.

For example:

USE ROLE developer_debugging;

-- Set the logging level to DEBUG for the current session.
ALTER SESSION SET LOG_LEVEL = DEBUG;

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If the level parameter is set to different levels for the current session and on the functions and procedures called in that session, Snowflake determines the effective level to use. See Understanding how Snowflake determines level in effect.

Understanding how Snowflake determines level in effect¶

You can override the telemetry level-related parameters (for both objects and sessions) by using a hierarchy of levels.

For example, you can set a level to one value for the account, then override it by setting the level for an object, which is lower in the hierarchy.

The following describes the hierarchy for session and object level parameters.

For session parameters, the hierarchy is Account » User » Session.

This means that you can set the parameter for an account, override the account-level parameter for a user, and override the user-level parameter for the current session.
For object parameters, the hierarchy is Account » Database » Schema » Object.

This means that you can set the parameter for an account, override the account-level parameter for a database or schema, and override the database- or schema-level parameter for specific stored procedures and UDFs in that database or schema.

For example, the LOG_LEVEL for a function overrides the LOG_LEVEL for the account that contains the function. If the LOG_LEVEL for the account is FATAL and the LOG_LEVEL for the Java UDF in the account is INFO, the effective LOG_LEVEL is INFO (the level for the function, not the account):

ALTER ACCOUNT SET LOG_LEVEL = FATAL;

ALTER FUNCTION MyJavaUDF SET LOG_LEVEL = INFO;

-- The INFO log level is used because the FUNCTION MYJAVAUDF
-- is lower than the ACCOUNT in the hierarchy.

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In cases where the level is set in both the session and object parameter hierarchies, the most verbose level is used.

For log level, the following table lists examples of how parameters set on the session and object affect the log level used.

Value for the Session

Value for the Object, Schema, Database, or Account

Log Level Used

(unset)

WARN

WARN

DEBUG

(unset)

DEBUG

WARN

ERROR

WARN

INFO

DEBUG

DEBUG

(unset)

(unset)

OFF
For metric level — ALL overrides NONE.
For trace level — ALWAYS overrides ON_EVENT and OFF; ON_EVENT overrides OFF.

Value for the Session	Value for the Object, Schema, Database, or Account	Log Level Used
(unset)	`WARN`	`WARN`
`DEBUG`	(unset)	`DEBUG`
`WARN`	`ERROR`	`WARN`
`INFO`	`DEBUG`	`DEBUG`
(unset)	(unset)	`OFF`