```
cd /usr/hdp/current/spark2-client
su spark
```

- Run the Apache Spark Pi job in yarn-client mode, using code from **org.apache.spark**:

```
./bin/spark-submit --class org.apache.spark.examples.SparkPi \
    --master yarn-client \
    --num-executors 1 \
    --driver-memory 512m \
    --executor-memory 512m \
    --executor-cores 1 \

        CountDownLatch latch = new CountDownLatch(sessionCount);

        for (int i = 0; i < sessionCount; i++) {
            final int sessionIndex = i;
            executor.submit(() -> {
                try {
                    String sessionId = "concurrent-session-" + sessionIndex;
                    byte[] salt = preauthService.generatePreauthSalt();

				</div>
			</div>

			<div class="row justify-content-center">
				<div class="col-auto">
					<button type="submit" name="search" id="searchButton"
						class="btn btn-primary mx-auto">
						<em class="fa fa-search">
						<la:message key="labels.index_form_search_btn" />
					</button>
				</div>
			</div>
		</main>

    for (int i = 0; i < nTasks; i++) {
      String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              new Runnable() {
                @Override
                public void run() {
                  cache.getUnchecked(s);
                  computedCount.incrementAndGet();

    for (int i = 0; i < nTasks; i++) {
      String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              new Runnable() {
                @Override
                public void run() {
                  cache.getUnchecked(s);
                  computedCount.incrementAndGet();

errors.app.db.already.updated = Il a peut-être été mis à jour par un autre processus. Veuillez réessayer.
errors.app.db.already.exists = Les données existent déjà. Veuillez réessayer.
errors.app.double.submit.request = Il a peut-être été traité avant cette requête. Veuillez réessayer.
# _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
# you can define your messages here:
# e.g.

errors.login.failure = 登录失败。
errors.app.illegal.transition = 非法转换，请重试。
errors.app.db.already.deleted = 可能已被其他进程删除。请重试。
errors.app.db.already.updated = 可能已被其他进程更新。请重试。
errors.app.db.already.exists = 数据已存在。请重试。
errors.app.double.submit.request = 此请求可能已在之前处理。请重试。
# _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
# you can define your messages here:
# e.g.
# errors.xxx = ...
# info.xxx = ...
# _/_/_/_/_/_/_/_/_/_/

      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent

      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent

4. **Add** comprehensive tests for new functionality
5. **Commit** your changes: `git commit -m 'Add amazing feature'`
6. **Push** to the branch: `git push origin feature/amazing-feature`
7. **Submit** a Pull Request with detailed description

### Code Standards
- Follow the project's Eclipse formatter configuration
- Add Apache License 2.0 headers to new files: `mvn license:format`