Hi everyone,
wonder if there is some work planned in tomcat 10 to 1. makes it start
faster and 2. make jmx optional.
I did some tests and locally a tomcat start is about 400ms.
I was surprised to see that Registry.disableRegistry() was taking already
65ms whereas it should be almost nothing so refactored the code, added a
RegistryFactory and really noop impl (not even a mock) and went down to
1ms, way better right? except the remaining 64ms went to the next line (new
StandardHost()). After some investigation time is mainly classloading time
(in all senses).
So I wonder if it wouldnt make sense to optimize tomcat startup time +
finally make JMX optional since it is no more used by users in most cases -
gues we must keep it as an optional plugin since it is used "historically".
The proposal would be to:
1. reduce classloading tree as much as possible for default case - here
having jmx optional will help a lot
2. probably generate resource bundle as .java at build time to avoid all
the classloading resource bundle implies (it is like 74 loadClass + as much
getResource for a simple startup and all loadclass are misses)
2.bis. probably add a mode where StringManager uses the default bundle
without passing through the resource bundle layer
3. cut dead code when we know it is inactive (typically the case for jmx)
4. open point: bypassing Context: in "main" mode (as the code shared
after), you just want to bind some logic in a servlet/filter/valve, you
don't always care about handling contexts (or a single one) so wonder if we
shouldnt evaluate the fact to add the user logic in a valve for this kind
of bench and maybe document this case (spring boot could inherit from it
since it almost never use anything else that default spring servlet and
binds everything in it).
Here is the kind of case I'd like to see insanely fast (<100ms - and it is
possible regarding what it does):
public class Main {
public static void main(String[] args) throws LifecycleException,
InterruptedException {
final long start = System.nanoTime();
Registry.disableRegistry();
final long startDisableRegistry = System.nanoTime();
final Host host = new StandardHost();
host.setName("localhost");
final long startHost = System.nanoTime();
final Engine engine = new StandardEngine();
engine.setName("Tomcat");
engine.setDefaultHost("localhost");
engine.setRealm(new NullRealm());
engine.addChild(host);
final long startEngine = System.nanoTime();
final var protocolHandler = new Http11Nio2Protocol();
protocolHandler.setPort(8080);
final long startHttp11Nio2Protocol = System.nanoTime();
final Service service = new StandardService();
service.setName("Tomcat");
service.setContainer(engine);
service.addConnector(new Connector(protocolHandler));
final long startService = System.nanoTime();
final StandardServer server = new StandardServer();
server.setPort(-1);
server.addService(service);
final long startServer = System.nanoTime();
final StandardContext context = new StandardContext();
context.setUseNaming(false);
context.setClearReferencesStopThreads(false);
context.setClearReferencesStopTimerThreads(false);
context.setClearReferencesHttpClientKeepAliveThread(false);
context.setClearReferencesRmiTargets(false);
context.setClearReferencesThreadLocals(false);
context.setClearReferencesObjectStreamClassCaches(false);
context.setWorkDir(System.getProperty("java.io.tmpdir"));
context.setName("");
context.setPath("");
context.setDocBase(null);
context.addLifecycleListener(event -> {
if (event.getType().equals(Lifecycle.CONFIGURE_START_EVENT)) {
context.setConfigured(true);
if (context.getLoginConfig() == null) {
context.setLoginConfig(new LoginConfig("NONE", null,
null, null));
context.getPipeline().addValve(new
NonLoginAuthenticator());
}
}
});
context.addServletContainerInitializer((classes, ctx) -> {
ctx.addServlet("default", new DefaultServlet())
.addMapping("/");
}, Set.of());
final long startContext = System.nanoTime();
host.addChild(context);
server.init();
final long inited = System.nanoTime();
server.start();
final long started = System.nanoTime();
// new CountDownLatch(1).await();
final var contextClassLoader =
Thread.currentThread().getContextClassLoader();
server.stop();
server.destroy();
final long stopped = System.nanoTime();
System.out.println(TimeUnit.NANOSECONDS.toMillis(started - start) +
"ms");
System.out.println(TimeUnit.NANOSECONDS.toMillis(stopped - started)
+ "ms");
System.out.println();
System.out.println("startDisableRegistry: " +
TimeUnit.NANOSECONDS.toMillis(startDisableRegistry - start) + "ms");
System.out.println("startHost: " +
TimeUnit.NANOSECONDS.toMillis(startHost - startDisableRegistry) + "ms");
System.out.println("startEngine: " +
TimeUnit.NANOSECONDS.toMillis(startEngine - startHost) + "ms");
System.out.println("startHttp11Nio2Protocol: " +
TimeUnit.NANOSECONDS.toMillis(startHttp11Nio2Protocol - startEngine) +
"ms");
System.out.println("startService: " +
TimeUnit.NANOSECONDS.toMillis(startService - startEngine) + "ms");
System.out.println("startServer: " +
TimeUnit.NANOSECONDS.toMillis(startServer - startService) + "ms");
System.out.println("startContext: " +
TimeUnit.NANOSECONDS.toMillis(startContext - startServer) + "ms");
System.out.println("actualInit: " +
TimeUnit.NANOSECONDS.toMillis(inited - startContext) + "ms");
System.out.println("actualStart: " +
TimeUnit.NANOSECONDS.toMillis(started - inited) + "ms");
}
}
Current reference output (medium values) is - on java 11:
364ms
22ms
startDisableRegistry: 58ms
startHost: 19ms
startEngine: 7ms
startHttp11Nio2Protocol: 25ms
startService: 39ms
startServer: 12ms
startContext: 26ms
actualStart: 200ms
Wdyt? Anyone had a look before?
PS: if curious the registry patch i did was:
https://gist.github.com/rmannibucau/e7cb9674fa4a21ccfe9eb956b509fad1 -
indeed since it does not help overall I don't ask to integrate it at all,
just a FYI
Romain Manni-Bucau
@rmannibucau <https://twitter.com/rmannibucau> | Blog
<https://rmannibucau.metawerx.net/> | Old Blog
<http://rmannibucau.wordpress.com> | Github <https://github.com/rmannibucau> |
LinkedIn <https://www.linkedin.com/in/rmannibucau> | Book
<https://www.packtpub.com/application-development/java-ee-8-high-performance>
