Hi guys,
We should actively notify/teach each other about tips and
tricks.
There's a lot we can learn from each other.
I'll start with a build tip:
The problem
========
- How bloated is the dependency tree of my module? This
affects the download zip size, but also the minimal jars
needed to run.
- Are there dead dependency left in my module?
The solution
========
- First thing to understand is that it has to reviewed
module by module
(focus on end-user modules such as drools-compiler,
drools-camel-server, guvnor-webapp, ...).
- Use the command
mvn dependency:tree
Example
=====
Here's the output on drools-compiler.
I've annotated a couple of possible incidents which might or
might not be a problem.
It's hard to tell without someone with extensive
drools-compiler experience looking further into it.
drools-compiler [master] $ mvn dependency:tree
[INFO] Scanning for projects...
[INFO]
[INFO]
------------------------------------------------------------------------
[INFO] Building Drools :: Compiler 5.3.0-SNAPSHOT
[INFO]
------------------------------------------------------------------------
[INFO]
[INFO] --- maven-dependency-plugin:2.2:tree (default-cli) @
drools-compiler ---
[INFO] org.drools:drools-compiler:jar:5.3.0-SNAPSHOT
[INFO] +- org.drools:drools-core:jar:5.3.0-SNAPSHOT:compile
[INFO] | \-
org.drools:knowledge-api:jar:5.3.0-SNAPSHOT:compile
[INFO] +-
org.drools:drools-core:test-jar:tests:5.3.0-SNAPSHOT:test
[INFO] +- org.apache.felix:org.osgi.core:jar:1.4.0:provided
[INFO] +-
org.apache.felix:org.osgi.compendium:jar:1.4.0:provided
[INFO] +- org.antlr:
antlr-runtime:jar:3.3:compile
[INFO] +- org.antlr:
antlr:jar:3.3:compile
Incident 1: maybe org.antlr:antlr-runtime:jar:3.3
is a subset of org.antlr:antlr-runtime:jar:3.3 ? (antlr is
wierd IIRC - so this is probably not in this case)
[INFO] +- org.antlr:stringtemplate:jar:3.2.1:compile
[INFO] +- antlr:
antlr:jar:2.7.7:compile
Incident 2: maybe antlr:antlr:jar:2.7.7 is a
subset of org.antlr:antlr-runtime:jar:3.3 ? (antlr is wierd
IIRC - so this is probably not in this case)
In general, dependencies with a non-namespaced groupId
need to be upgraded if possible.
[INFO] +- org.antlr:gunit:jar:3.3:test
[INFO] +-
org.eclipse.jdt.core.compiler:ecj:jar:3.5.1:compile
[INFO] +- janino:janino:jar:2.5.15:compile
Note that janino is optional (output doesn't show that :(
) - no problem here
[INFO] +- org.mvel:mvel2:jar:2.1-SNAPSHOT:compile
[INFO] +- com.thoughtworks.xstream:xstream:jar:1.3.1:test
[INFO] | \- xpp3:xpp3_min:jar:1.1.4c:test
[INFO] +- org.mortbay.
jetty:jetty-embedded:jar:6.1.15:test
Incident 3: Wierd that drools-compiler would need
jetty to test something?
[INFO] | +- org.mortbay.jetty:jetty:jar:6.1.15:test
[INFO] | | +- org.mortbay.jetty:jetty-util:jar:6.1.15:test
[INFO] | | \-
org.mortbay.jetty:servlet-api:jar:2.5-20081211:test
[INFO] | \- javax.servlet.jsp:jsp-api:jar:2.1:test
[INFO] +- org.opensymphony.quartz:quartz:jar:1.6.1:test
[INFO] +- com.sun.xml.bind:jaxb-xjc:jar:2.2.1.1:provided
[INFO] +- com.sun.xml.bind:jaxb-impl:jar:2.2.1.1:provided
[INFO] +- javax.xml.bind:jaxb-api:jar:2.2.1:provided
[INFO] +- javax.xml.stream:stax-api:jar:1.0-2:provided
[INFO] +- javax.activation:activation:jar:1.1:provided
[INFO] +- net.java.dev.
glazedlists:glazedlists_java15:jar:1.8.0:test
Incident 4: Wierd that drools-compiler would need
a swing framework to test something?
[INFO] +- junit:junit:jar:4.8.1:test
[INFO] \- org.mockito:mockito-all:jar:1.8.2:test
[INFO]
------------------------------------------------------------------------
[INFO] BUILD
SUCCESS &nbs
p;
[INFO]
------------------------------------------------------------------------
;
[INFO] Total time:
1.951s
;
[INFO] Finished at: Wed May 11 15:09:09 CEST
2011 &
nbsp;
[INFO] Final Memory:
10M/309M &nb
sp;
[INFO]
------------------------------------------------------------------------
Here's another example showing another type of incident:
drools-camel-server [master] $ mvn dependency:tree
...
[INFO] +-
org.drools:drools-grid-impl:jar:5.3.0-SNAPSHOT:compile
[INFO] | +- org.apache.mina:mina-core:jar:2.0.1:compile
(version managed from 2.0.0-M6)
[INFO] | \- com.hazelcast:hazelcast:jar:1.8.5:compile
...
[INFO] +- org.apache.camel:camel-cxf:jar:2.4.0:compile
[INFO] | \- org.apache.cxf:
cxf-rt-frontend-jaxrs:jar:2.2.9:compile
[INFO] | +-
org.apache.cxf:cxf-common-utilities:jar:2.2.9:compile
[INFO] | +-
org.apache.cxf:cxf-rt-transports-http:jar:2.2.9:compile
[INFO] | +-
org.apache.cxf:cxf-rt-databinding-aegis:jar:2.2.9:compile
[INFO] | +- jaxen:jaxen:jar:1.1.1:compile
[INFO] | \-
org.apache.xmlbeans:xmlbeans:jar:2.4.0:compile
...
[INFO] +- org.apache.cxf:
cxf-bundle-jaxrs:jar:2.2.9:compile
Incident A: This cxf-bundle-jaxrs is an uber jar.
Uber jars (as dependencies) are evil.
An uber jar extracts the classes from other jars and
zips them (=aggregate) in itself.
This effectively kills maven's ability to only have 1
class of something in your classpath.
It turns your classpath into box of chocolates:
you
never know what version of class file you'll get.
Also, it bloats the classpath with things you don't
need (like jetty in this case)
and those cause havoc if you deploy it to some app
servers.
[INFO] | +- aopalliance:aopalliance:jar:1.0:compile
[INFO] | +-
org.apache.geronimo.specs:geronimo-annotation_1.0_spec:jar:1.1.1:compile
[INFO] | +-
org.apache.geronimo.specs:geronimo-stax-api_1.0_spec:jar:1.0.1:compile
[INFO] | +- wsdl4j:wsdl4j:jar:1.6.2:compile
[INFO] | +-
org.apache.ws.commons.schema:XmlSchema:jar:1.4.5:compile
[INFO] | +- commons-lang:commons-lang:jar:2.4:compile
[INFO] | +-
org.apache.geronimo.specs:geronimo-activation_1.1_spec:jar:1.0.2:compile
[INFO] | +-
org.codehaus.woodstox:wstx-asl:jar:3.2.9:compile
[INFO] | +- org.apache.neethi:neethi:jar:2.0.4:compile
[INFO] | +-
org.apache.geronimo.specs:geronimo-javamail_1.4_spec:jar:1.6:compile
[INFO] | +-
org.springframework:spring-web:jar:2.5.6:compile
[INFO] | +- org.mortbay.jetty:
jetty:jar:6.1.21:compile
[INFO] | +- org.mortbay.jetty:jetty-util:jar:6.1.21:compile
[INFO] | +- javax.ws.rs:jsr311-api:jar:1.0:compile
[INFO] | +- org.apache.abdera:abdera-core:jar:1.0:compile
[INFO] | +- org.apache.abdera:abdera-i18n:jar:1.0:compile
[INFO] | +- commons-codec:commons-codec:jar:1.3:compile
[INFO] | +- org.apache.abdera:abdera-parser:jar:1.0:compile
[INFO] | +-
org.apache.ws.commons.axiom:axiom-impl:jar:1.2.7:compile
[INFO] | +-
org.apache.ws.commons.axiom:axiom-api:jar:1.2.7:compile
[INFO] | +-
org.apache.abdera:abdera-extensions-json:jar:1.0:compile
[INFO] | \-
org.apache.abdera:abdera-extensions-main:jar:1.0:compile
...
Also, if you're trying to solve such things on master, try
upgrading the dependencies first (not on a release branch -
upgrading is risky!):
many issues in the poms tend to be identified and fixed in
newer versions.
--
With kind regards,
Geoffrey De Smet