BacklogTracer Interceptor
Since Camel 2.11
Camel supports a backlog tracer interceptor that is used for capturing a
trace message of each message as they are routed in Camel.
The trace message is stored in a backlog queue, which contains the last
N messages for each node in the routes (by default 10).
The BacklogTracer is an InterceptStrategy which can be applied to a DefaultCamelContext or SpringCamelContext to ensure that there is a TracerInterceptor created for every node in the DSL.
You can enable or disable the BacklogTracer’s logging dynamically, by
calling the backlogTracer’s setEnabled
method.
What is the difference between BacklogTracer and Tracer
Camel also provides a Tracer which has similar
capabilities as this backlog tracer. The difference is that the backlog
tracer is storing
a capture of the message in an internal backlog queue. Where as the
Tracer is event based and logs the messages as they
happen (or route to another Camel destination). Also the
Tracer has more fine grained events where it dives
into EIPs such as the
Content Based Router and traces the
when/otherwise(s). Though the Tracer has much more
complicated logic to handle this (there is some edge-cases where this
may not work). The BacklogTracer allows you to pull the messages from
the backlog queues on demand. The BacklogTracer works better with JMX
capable tooling as it is simpler and allow to bulk dump all its traced
messages in either a POJO or XML format. And there is a Karaf command
for the BacklogTracer which allows you to control the tracing from a
Karaf shell.
Options
Option | Default |
---|---|
Description |
enabled |
|
Flag to enable or disable this tracer |
backlogSize |
|
Maximum number of total traced messages to keep in the backlog (FIFO queue). |
tracePattern |
|
Allows to filter tracing using a pattern that matches against the node
id and route id. For example use |
traceFilter |
|
Allow to configure a filter as a Predicate using
any of the Camel languages. But default the
Simple language is used. For example to filter on
messages with a given header, use |
removeOnDump |
|
Whether to remove the traced messages that was returned when invoking the dump methods. |
bodyMaxChars |
|
To limit the message body to a maximum size in the traced message. Use 0 or negative value to use unlimited size. |
bodyIncludeStreams |
|
Whether to include the message body of stream based messages. If enabled then beware the stream may not be re-readable later. See more about Stream Caching. |
bodyIncludeFiles |
|
Operations
Option | Default |
---|---|
Description |
getTraceCounter |
|
Gets the total number of traced messages. |
resetTraceCounter |
|
To reset the trace counter. |
dumpTracedMessages(nodeOrRouteId) |
|
To dump the traced messages from the give node or route id. |
dumpTracedMessagesAsXml(nodeOrRouteId) |
|
To dump the traced messages from the give node or route id in XML format. |
dumpAllTracedMessages |
|
To dump all the traced messages |
dumpAllTracedMessagesAsXml |
|