8. Logging support

An appender for Log4j is provided in the maven module "spring-data-mongodb-log4j". Note, there is no dependency on other Spring Mongo modules, only the MongoDB driver.

8.1 MongoDB Log4j Configuration

Here is an example configuration

log4j.rootCategory=INFO, stdout

log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - <%m>%n
log4j.appender.stdout.host = localhost 
log4j.appender.stdout.port = 27017
log4j.appender.stdout.database = logs
log4j.appender.stdout.collectionPattern = %X{year}%X{month}
log4j.appender.stdout.applicationId = my.application
log4j.appender.stdout.warnOrHigherWriteConcern = FSYNC_SAFE


The important configuration to look at aside from host and port is the database and collectionPattern. The variables year, month, day and hour are available for you to use in forming a collection name. This is to support the common convention of grouping log information in a collection that corresponds to a specific time period, for example a collection per day.

There is also an applicationId which is put into the stored message. The document stored from logging as the following keys: level, name, applicationId, timestamp, properties, traceback, and message.