[improve][broker] Skip loading the NAR packages if not configured

[BewareMyPower]

Motivation

When loading NAR packages, including broker interceptors, additional servlets and protocol handlers, even if they are not configured, the NAR packages are still loaded, which is unnecessary and slows the restarting of a broker.

Modifications

Skip searching the directories and loading NAR packages when no plugin is configured, including:

• BrokerInterceptors#load
• AdditionalServlets#load
• ProtocolHandlers#load

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository:

[lhotari]

@BewareMyPower Nice improvement. How about applying this also to src/main/java/org/apache/pulsar/proxy/extensions/ProxyExtensions.java. ?
Here:

pulsar/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/extensions/ProxyExtensions.java

Lines 51 to 85 in 82237d3

	public static ProxyExtensions load(ProxyConfiguration conf) throws IOException {
	ExtensionsDefinitions definitions =
	ProxyExtensionsUtils.searchForExtensions(
	conf.getProxyExtensionsDirectory(), conf.getNarExtractionDirectory());
	ImmutableMap.Builder<String, ProxyExtensionWithClassLoader> extensionsBuilder = ImmutableMap.builder();
	conf.getProxyExtensions().forEach(extensionName -> {
	ProxyExtensionMetadata definition = definitions.extensions().get(extensionName);
	if (null == definition) {
	throw new RuntimeException("No extension is found for extension name `" + extensionName
	+ "`. Available extensions are : " + definitions.extensions());
	}
	ProxyExtensionWithClassLoader extension;
	try {
	extension = ProxyExtensionsUtils.load(definition, conf.getNarExtractionDirectory());
	} catch (IOException e) {
	log.error("Failed to load the extension for extension `" + extensionName + "`", e);
	throw new RuntimeException("Failed to load the extension for extension name `" + extensionName + "`");
	}
	if (!extension.accept(extensionName)) {
	extension.close();
	log.error("Malformed extension found for extensionName `" + extensionName + "`");
	throw new RuntimeException("Malformed extension found for extension name `" + extensionName + "`");
	}
	extensionsBuilder.put(extensionName, extension);
	log.info("Successfully loaded extension for extension name `{}`", extensionName);
	});
	return new ProxyExtensions(extensionsBuilder.build());
	}

[BewareMyPower]

@lhotari Good suggestion. I applied the check to ProxyExtensions now.

[codecov-commenter]

Codecov Report

Attention: 25 lines in your changes are missing coverage. Please review.

Comparison is base (cea5c93) 73.59% compared to head (40f67bd) 73.61%.
Report is 5 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #21867      +/-   ##
============================================
+ Coverage     73.59%   73.61%   +0.01%     
- Complexity    32323    32347      +24     
============================================
  Files          1858     1859       +1     
  Lines        138174   138281     +107     
  Branches      15148    15156       +8     
============================================
+ Hits         101696   101801     +105     
+ Misses        28608    28598      -10     
- Partials       7870     7882      +12     

Flag	Coverage Δ
inttests	24.10% <4.47%> (-0.15%)	⬇️
systests	23.71% <16.41%> (-0.08%)	⬇️
unittests	72.90% <62.68%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...pache/pulsar/broker/protocol/ProtocolHandlers.java	83.33% <100.00%> (+0.57%)	⬆️
...ervice/AbstractDispatcherSingleActiveConsumer.java	90.55% <100.00%> (ø)
...va/org/apache/pulsar/broker/service/ServerCnx.java	72.33% <100.00%> (-0.07%)	⬇️
...rg/apache/pulsar/client/impl/TopicListWatcher.java	67.85% <100.00%> (+1.19%)	⬆️
...pache/pulsar/proxy/extensions/ProxyExtensions.java	82.14% <100.00%> (+0.66%)	⬆️
...rg/apache/pulsar/broker/service/AbstractTopic.java	87.86% <0.00%> (-0.15%)	⬇️
...he/pulsar/broker/intercept/BrokerInterceptors.java	61.53% <33.33%> (-6.29%)	⬇️
.../broker/web/plugin/servlet/AdditionalServlets.java	63.41% <25.00%> (-3.26%)	⬇️
...ar/client/impl/PatternMultiTopicsConsumerImpl.java	82.70% <61.22%> (-5.26%)	⬇️

... and 79 files with indirect coverage changes