AravindaM

FROM openjdk:8
WORKDIR /app
ENV JAVA_TOOL_OPTIONS -agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n
COPY remote-debugging-1.0-SNAPSHOT.jar  remote-debugging.jar
ENTRYPOINT ["java", "-cp", "remote-debugging.jar", "com.kaysush.App"]

AravindaM

How to filter an entry from a stream in Java

1. Using .flatmap

List<Integer> numbers = listOfStrings.stream()
        .flatMap(s -> {
            try {
                return Stream.of(Integer.parseInt(s));
 } catch (Exception e) {

AravindaM

import java.io.IOException;
import java.net.URISyntaxException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;

AravindaM

Enable native memory tracking in JVM by specifying the following flag

-XX:NativeMemoryTracking=detail

Know the <PID> of the java process

jps

To print ps based RSS

ps -p <PID> -o pcpu,rss,size,vsize

To print native memory tracking summary

AravindaM

Node.js TLS plain TLS sockets

This guide shows how to set up a bidirectional client/server authentication for plain TLS sockets.

Prepare certificates

Generate a Certificate Authority:

openssl req -new -x509 -days 9999 -keyout ca-key.pem -out ca-crt.pem

AravindaM

#Get osx process listining on port 8081
lsof -i tcp:8081

AravindaM

import org.springframework.boot.actuate.health.AbstractHealthIndicator;
import org.springframework.boot.actuate.health.Health;
import org.springframework.stereotype.Component;

@Component
public class AddCustomHealthIndicator extends AbstractHealthIndicator {

    @Override
    protected void doHealthCheck(Health.Builder builder) {

AravindaM

The repository for the assignment is public and Github does not allow the creation of private forks for public repositories.

The correct way of creating a private frok by duplicating the repo is documented here.

For this assignment the commands are:

1. Create a bare clone of the repository. (This is temporary and will be removed so just do it wherever.)

git clone --bare git@github.com:usi-systems/easytrace.git

AravindaM

### KERNEL TUNING ###

# Increase size of file handles and inode cache
fs.file-max = 2097152

# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 60
vm.dirty_background_ratio = 2

AravindaM

import jdk.incubator.http.HttpClient;
import jdk.incubator.http.HttpRequest;
import jdk.incubator.http.HttpResponse;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

public class Http2client {