This Channel implements logging to a SQL database. The channel is dependent on the schema. The DDL for table creation (subject to target DDL dialect dependent modifications) is:

"CREATE TABLE T_POCO_LOG (Source VARCHAR, Name VARCHAR, ProcessId INTEGER, Thread VARCHAR, ThreadId INTEGER, Priority INTEGER, Text VARCHAR, DateTime DATE)"

The table name is configurable through "table" property. Other than DateTime filed name used for optional time-based archiving purposes, currently the field names are not mandated. However, it is recommended to use names as specified above.

To provide as non-intrusive operation as possible, the log entries are cached and inserted into the target database asynchronously by default. The blocking, however, will occur before the next entry insertion with default timeout of 1 second. The default settings can be overridden (see async, timeout and throw properties for details). If throw property is false, insertion timeouts are ignored, otherwise a TimeoutException is thrown. To force insertion of every entry, set timeout to 0. This setting, however, introduces a risk of long blocking periods in case of remote server communication delays.

A default-constructed SQLChannel operates without an active DB connection, in a store-and-forward mode. For this mode of operation, a separate service is required to consume and execute the SQL statements from the stored files and insert the log entries into the database. Since this setup stores SQL inserts in the OS file system, it is strongly recommended to take the necessary precautions to limit and secure the access to those files.

Creates SQLChannel. An SQLChannel without DB connector and local file name only logs SQL inserts into local files. A separate file is created for each insert batch; files are named <YYYYMMDDHH24MISSmmm>.<UUID>.log.sql.

Creates an SQLChannel with the given connector, connect string, timeout, table and name. The connector must be already registered.

Closes the SQLChannel.

See also: Poco::Channel::close()

Returns the value of the property with the given name.

See also: Poco::Channel::getProperty()

Returns true if the logging thread is running.

Writes the log message to the database.

See also: Poco::Channel::log()

Returns the number of logged entries.

Opens the SQLChannel. Returns true if succesful.

See also: Poco::Channel::open()

Registers the channel with the global LoggingFactory.

Dequeues and sends the logs to the DB.

See also: Poco::Runnable::run()

Sets the property with the given value.

The following properties are supported:

• name: The name used to identify the source of log messages. Defaults to "-".

• connector: The target data storage connector name.

• connect: The target data storage connection string.

• table: Destination log table name. Defaults to "T_POCO_LOG". Table must exist in the target database.

• keep: Max row age for the log table. To disable archiving, set this property to empty string or "forever".

• archive: Archive table name. Defaults to "T_POCO_LOG_ARCHIVE". Table must exist in the target database. To disable archiving, set this property to empty string.

• async: Indicates asynchronous execution. When excuting asynchronously, messages are sent to the target using asyncronous execution. However, prior to the next message being processed and sent to the target, the previous operation must have been either completed or timed out (see timeout and throw properties for details on how abnormal conditos are handled). This property is deprecated and has no effect - all logging is asynchronous since the 1.13.0. release.

• timeout: Timeout (ms) to wait for previous log operation completion. Values "0" and "" mean no timeout.

• throw: Boolean value indicating whether to throw in case of timeout. Setting this property to false may result in log entries being lost. True values are (case insensitive) "true", "t", "yes", "y". Anything else yields false.

• minBatch: Minimal number of log entries to accumulate before actually sending logs to the destination. Defaults to 1 entry (for compatibility with older versions); can't be zero or larger than maxBatch.