Scaling Java Application
Vers l’infini et au delà

Round 1 : Debug

Dépendances

version: '3'

services:

  postgresql:
    image: postgres:10.1
    ports:
      - 5432:5432

  hydra:
    image: oryd/hydra:v1.0.0-beta.9
    ports:
      - 4444:4444
      - 4445:4445
    command:
      serve all --dangerous-force-http

Round 1 : Debug

Lancement application

$ docker run -it -p 8080:8080 -p 1099:1099 \
  -e JAVA_OPTS='
    -Xms512m
    -Xmx512m
    -XX:MaxMetaspaceSize=128m
    -XX:+UseG1GC
    -XX:NativeMemoryTracking=summary
    -Djava.rmi.server.hostname=localhost
    -Dcom.sun.management.jmxremote
    -Dcom.sun.management.jmxremote.port=1099 ' \
   --memory 896m  \
  --memory-swap 896m \
  --name quoteengine_service \
  quoteengine_service
                        

Round 1 : Debug

Simulation latences

$ docker run --name quoteengine_pumba_hydra_1 -d \
    gaiaadm/pumba:master netem \
    --duration 3600m delay --time 500 quoteengine_hydra_1

$ docker run --name quoteengine_pumba_postgresql_1 -d \
    gaiaadm/pumba:master netem \
    --duration 3600m --time 200 quoteengine_postgresql_1
                        

Round 1 : Debug

Lancement des tests

Round 1 : Debug

Stats docker au lancement

Round 1 : Debug

Stats docker après 30s

Round 1 : Debug

Stats docker après 1min

Round 1 : Debug

Etat de l'application

Round 1 : Debug

Analyse mémoire

Round 1 : Debug

Recherche Bug JVM

Round 1 : Debug

Résolution

private static byte[] compress(byte[] data) throws IOException {
    Deflater deflater = new Deflater();
    deflater.setInput(data);
    try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length)) {
        deflater.finish();
        byte[] buffer = new byte[1024];
        while (!deflater.finished()) {
            int count = deflater.deflate(buffer);
            outputStream.write(buffer, 0, count);
        }
        return outputStream.toByteArray();
    } finally {
        deflater.end();
    }
}
                        

Round 1 : Tests

Round 2 : Debug

Lancement des tests

Round 2 : Debug

Visualisation des threads

Round 2 : Debug

Threads dump

Round 2 : Debug

Code source

JwkDefinitionHolder getDefinitionLoadIfNecessary(String keyId) {
    JwkDefinitionHolder result = this.getDefinition(keyId);
    if (result != null) {
        return result;
    }
    synchronized (this.jwkDefinitions) {
        this.jwkDefinitions.clear();
        for (URL jwkSetUrl : jwkSetUrls) {
            this.jwkDefinitions.putAll(loadJwkDefinitions(jwkSetUrl));
        }
        return this.getDefinition(keyId);
    }
}
                        

Round 2 : Debug

Résolution

JwkDefinitionHolder getDefinitionLoadIfNecessary(String keyId) {
    JwkDefinitionHolder result = this.getDefinition(keyId);
    if (result != null) {
        return result;
    }
    synchronized (this.jwkDefinitions) {

        // Double-checked locking pattern
        result = this.getDefinition(keyId);
        if (result != null) {
            return result;
        }

        this.jwkDefinitions.clear();
        for (URL jwkSetUrl : jwkSetUrls) {
            this.jwkDefinitions.putAll(loadJwkDefinitions(jwkSetUrl));
        }
        return this.getDefinition(keyId);
    }
}
                        

Round 2 : Tests

Round 3 : Debug

Activation logs

logging:
  level:
    org.springframework.jdbc.core: TRACE
                        

Round 3 : Debug

Logs Spring JDBC

Round 3 : Debug

Activation logs Driver

logging:
  level:
    org.postgresql.core.v3.QueryExecutorImpl: TRACE
                        

Round 3 : Debug

Logs Driver Postgresql

Round 3 : Debug

Break point driver Posgresql

Round 3 : Debug

Résolution

@Service
@Transactional
@RequiredArgsConstructor
public class TaxService {

  private final CacheManager cacheManager;

  public List<GlobalTax> getGlobalTaxes(String countryCode) {
    return Optional.ofNullable(getGlobalTaxCache().get(countryCode)).map(Cache.ValueWrapper::get).orElse(null);
  }

  private Cache getGlobalTaxCache() {
    return cacheManager.getCache(CacheConfiguration.GLOBAL_TAX_CACHE_NAME);
  }