Chapter 55. Log

Log Component

The log: component logs message exchanges to the underlying logging mechanism.

URI format

log:loggingCategory[?options]

Where loggingCategory is the name of the logging category to use. You can append query options to the URI in the following format, ?option=value&option=value&...

For example, a log endpoint typically specifies the logging level using the level option, as follows:

log:org.apache.camel.example?level=DEBUG

The default logger logs every exchange (regular logging). But Fuse Mediation Router also ships with the Throughput logger, which is used whenever the groupSize option is specified.

	Also a log in the DSL
	In Camel 2.2 onwards there is a `log` directly in the DSL, but it has a different purpose. Its meant for lightweight and human logs. See more details at LogEIP in Implementing Routes.

Options

Option	Default	Type	Description
`level`	`INFO`	`String`	Logging level to use. Possible values: `FATAL`, `ERROR`, `WARN`, `INFO`, `DEBUG`, `TRACE`, `OFF`
`groupSize`	`null`	`Integer`	An integer that specifies a group size for throughput logging.
`groupInterval`	`null`	`Integer`	Camel 2.6: If specified will group message stats by this time interval (in millis)
`groupDelay`	`0`	`Integer`	Camel 2.6: Set the initial delay for stats (in millis)
`groupActiveOnly`	`true`	`boolean`	Camel 2.6: If true, will hide stats when no new messages have been received for a time interval, if false, show stats regardless of message traffic

	Note
	`groupDelay` and `groupActiveOnly` are only applicable when using `groupInterval`.

Formatting

The log formats the execution of exchanges to log lines. By default, the log uses LogFormatter to format the log output, where LogFormatter has the following options:

Option	Default	Description
`showAll`	`false`	Quick option for turning all options on (multiline, maxChars has to be manually set if to be used).
`showExchangeId`	`false`	Show the unique exchange ID.
`showExchangePattern`	`true`	Camel 2.3: Shows the Message Exchange Pattern (or MEP for short).
`showProperties`	`false`	Show the exchange properties.
`showHeaders`	`false`	Show the In message headers.
`showBodyType`	`true`	Show the In body Java type.
`showBody`	`true`	Show the In body.
`showOut`	`false`	If the exchange has an Out message, show the Out message.
`showException`	`false`	Fuse Mediation Router 2.0: If the exchange has an exception, show the exception message (no stack trace).
`showCaughtException`	`false`	Fuse Mediation Router 2.0: If the exchange has a caught exception, show the exception message (no stack trace). A caught exception is stored as a property on the exchange and for instance a `doCatch` can catch exceptions. See Try Catch Finally.
`showStackTrace`	`false`	Fuse Mediation Router 2.0: Show the stack trace, if an exchange has an exception. Only effective if one of `showAll`, `showException` or `showCaughtException` are enabled.
`showFuture`	`false`	Camel 2.1: Whether Camel should show `java.util.concurrent.Future` bodies or not. If enabled Camel could potentially wait until the `Future` task is done. Will by default not wait.
`multiline`	`false`	If `true`, each piece of information is logged on a new line.
`maxChars`		Fuse Mediation Router 2.0: Limits the number of characters logged per line.

Regular logger sample

In the route below we log the incoming orders at DEBUG level before the order is processed:

from("activemq:orders").to("log:com.mycompany.order?level=DEBUG").to("bean:processOrder");

Or using XML to define the route:

  <route>
    <from uri="activemq:orders"/>
    <to uri="log:com.mycompany.order?level=DEBUG"/>
    <to uri="bean:processOrder"/>
  </route>

Regular logger with formatter sample

In the route below we log the incoming orders at INFO level before the order is processed.

from("activemq:orders").
    to("log:com.mycompany.order?showAll=true&multiline=true").to("bean:processOrder");

Throughput logger with groupSize sample

In the route below we log the throughput of the incoming orders at DEBUG level grouped by 10 messages.

from("activemq:orders").
    to("log:com.mycompany.order?level=DEBUG?groupSize=10").to("bean:processOrder");

Throughput logger with groupInterval sample

This route will result in message stats logged every 10s, with an initial 60s delay and stats should be displayed even if there isn't any message traffic.

from("activemq:orders")
    .to("log:com.mycompany.order?level=DEBUG?groupInterval=10000&groupDelay=60000&groupActiveOnly=false")
    .to("bean:processOrder");

The following will be logged:

"Received: 1000 new messages, with total 2000 so far. Last group took: 10000 millis which is: 100 messages per second. average: 100"