log-merger

Simple command line utility to merge different log files based on their timestamps preserving stacktraces.

Usage

To merge two log files which contain the timestamp in the format 2015-08-29T15:49:46,919 in the first column (columns are separated by space):

java -jar log-merger-0.0.2-jar-with-dependencies.jar -i in1.log,in2.log -o out.log -m -d " " -tf "yyyy-MM-dd'T'HH:mm:ss,SSS" -f 1

The available options are:

-d,--delimiter <del>            the delimiter
-f,--field <field(s)>           the field number(s) (comma separated) containing the timestamp
-i,--input <file(s)>            the log files (comma separated)
-m,--marker                     if a marker for each file should be inserted
-o,--output <file>              the output file
-tf,--timestamp-format <tf>     the timestamp format (e.g. yyyy-MM-dd'T'HH:mm:ss.SSSXXX)
-v,--verbose                    outputs additional logging information

When a file contains date and time in separate fields (e.g. 2015-08-29 14:15:30,472) you can provide the options -d " " -tf "yyyy-MM-dd'T'HH:mm:ss,SSS" -f 1,2 as the fields one and two are concatenated and parsed as one field according to the specified timestamp format.

The option --marker inserts a maker like [0] at the beginning of each line into the output to indicate from which file the current line stems. The input files are numbered (starting with zero) such that the marker [3] tells you the lines stems from the fourth input file.

If the option --input is not provided, the output is written to stdout. Hence you can use this tool in a pipeline with standard utilities like grep, cut, etc.

More information on how to specify the timestamp format can be found here. For httpd's access logs you can use for example: '['dd/MMM/yyyy:HH:mm:ss together with space as delimiter.

If a line does not contain the number of specified fields or does not contain a timestamp at the given fields, it is treated like it would belong to the last line with proper timestamp. This way the stacktrace of an exception is merged together with the timestamp line.

Using the option --verbose will output any errors happening during timestamp conversion to stderr. As lines that do not contain a valid timestamp will be appended to the last line with a valid timestamp, it can happen that the output is empty when specifying a wrong timestamp format or the wrong field as there is no last line to append the invalid line to.

Example:

file1.log:

2015-08-29 15:49:46,641 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-4) MSC000001: Failed to start service jboss.undertow.listener.default: org.jboss.msc.service.StartException in service jboss.undertow.listener.default: Could not start http listener
	at org.wildfly.extension.undertow.ListenerService.start(ListenerService.java:150)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.BindException: Die Adresse wird bereits verwendet
	at sun.nio.ch.Net.bind0(Native Method)
	at sun.nio.ch.Net.bind(Net.java:436)
	at sun.nio.ch.Net.bind(Net.java:428)
	at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:214)
	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:67)
	at org.xnio.nio.NioXnioWorker.createTcpConnectionServer(NioXnioWorker.java:182)
	at org.xnio.XnioWorker.createStreamConnectionServer(XnioWorker.java:243)
	at org.wildfly.extension.undertow.HttpListenerService.startListening(HttpListenerService.java:115)
	at org.wildfly.extension.undertow.ListenerService.start(ListenerService.java:147)
	... 5 more

file2.log:

2015-08-29 15:49:46,033 INFO  [org.xnio] (MSC service thread 1-3) XNIO version 3.3.1.Final

output:

[1] 2015-08-29 15:49:46,033 INFO  [org.xnio] (MSC service thread 1-3) XNIO version 3.3.1.Final
[0] 2015-08-29 15:49:46,641 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-4) MSC000001: Failed to start service jboss.undertow.listener.default: org.jboss.msc.service.StartException in service jboss.undertow.listener.default: Could not start http listener
[0] 	at org.wildfly.extension.undertow.ListenerService.start(ListenerService.java:150)
[0] 	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948)
[0] 	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881)
[0] 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
[0] 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
[0] 	at java.lang.Thread.run(Thread.java:745)
[0] Caused by: java.net.BindException: Die Adresse wird bereits verwendet
[0] 	at sun.nio.ch.Net.bind0(Native Method)
[0] 	at sun.nio.ch.Net.bind(Net.java:436)
[0] 	at sun.nio.ch.Net.bind(Net.java:428)
[0] 	at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:214)
[0] 	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
[0] 	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:67)
[0] 	at org.xnio.nio.NioXnioWorker.createTcpConnectionServer(NioXnioWorker.java:182)
[0] 	at org.xnio.XnioWorker.createStreamConnectionServer(XnioWorker.java:243)
[0] 	at org.wildfly.extension.undertow.HttpListenerService.startListening(HttpListenerService.java:115)
[0] 	at org.wildfly.extension.undertow.ListenerService.start(ListenerService.java:147)
[0] 	... 5 more

Download

You can download a copy of log-merger from the downloads page.