[Feature] Make bytebuddy ignore some classes to speed up startup time

[SunJiFengPlus]

Search before asking

• I had searched in the issues and found no similar feature requirement.

Description

In our company's promotion of Skywalking, we found that some project team feedback after adding Skywalking-java will make the application startup time longer (35s -> 60s). The way to verify this is to use JMeter to continuously send Http requests to the application, then record the time and start the application again, until JMeter's request no longer return error, then calculate the time gap.

I've hardcoded the time spent on the following methods

• SkyWalkingAgent#premian
• SkyWalkingAgent.Transformer#transform
• ProtectiveShieldMatcher#matches

like this

    @Override
    public boolean matches(T target) {
        try {
            if (LOGGER.isDebugEnable()) {
                long start = System.currentTimeMillis();
                boolean matches = this.matcher.matches(target);
                COST.addAndGet(System.currentTimeMillis() - start);
                LOGGER.debug("So far the Byte-buddy matches has took : {} ms", COST.get());
                return matches;
            } else {
                return this.matcher.matches(target);
            }
        } catch (Throwable t) {
            if (LOGGER.isDebugEnable()) {
                LOGGER.debug(t, "Byte-buddy occurs exception when match type.");
            }
            return false;
        }
    }

Until the application is able to handle http requests correctly, the most time-consuming method is ProtectiveShieldMatcher#matches, it cost 16s+. The application contains a large number of classes, mostly prefixed with com.our.company, which do not need to be enhanced. I got a huge reduction in startup time by ignoring this prefixed class in Bytebuddy.

Use case

For applications that are sensitive to startup time and require fast deployment and scaling, applications are less tolerant of increased startup time. Reduce the startup time increase by ignoring classes that enhance the specified prefix. This prefix can probably be configured in agent.config

Related issues

No response

Are you willing to submit a pull request to implement this on your own?

• Yes I am willing to submit a pull request on my own!

Code of Conduct

• I agree to follow this project's Code of Conduct

[wu-sheng]

If your app is sensitive like such, please do that internally.
For upstream, it is hard to do like this. Because it conflicts with some plugins matching claas by parent class or interfaces or both.
We can't exclude those classes

[SunJiFengPlus]

User must know the class prefix of the plugin before configuring, otherwise the plugin will not work. It's a bit more complicated, but it's a workable solution with a large number of classes.
Is it possible to have this feature as a configuration item? By default it is not ignored, but can be configured to reduce startup time for some time sensitive applications.

[wu-sheng]

You are thinking easily. From my experience, I am suffering ppl even don't read either docs or logs. You asks me to trust them to read source codes, sorry, I can't.
I would not say yes to upstream for this manual configuration.
Sorry again, I am suffering heavily payload to answer naive questions because most of ppl of oss is just doing as a blog says, or some others told them.

[wu-sheng]

This is not from days or months. I experienced this for 8 years, nothing changed.

[SunJiFengPlus]

okay, I'm sure you're right. The solution within my company is that we only take out the config item when a other team comes to us and tell them how to fill it in, even then there are a lot of problems.