They tend to require more complex configurations, a message/job queue manager, like RabbitMQ or Redis, but they allow you to run background tasks in multiple processes, and especially, in multiple servers.

        assertEquals(0, events.size());
    }

    @Test
    public void test_append_excludedLogger_logNotificationJob() {
        final LogEvent event = createLogEvent(Level.ERROR, "org.codelibs.fess.job.LogNotificationJob", "should be excluded");
        appender.append(event);

        final List<LogNotificationEvent> events = ComponentUtil.getLogNotificationHelper().drainAll();
        assertEquals(0, events.size());

        createFileConfig();
        logger.info("FileConfig is created");
        refresh();
        fileConfigId = getFileConfigIds(NAME_PREFIX).get(0);

        createJob();
        logger.info("Job is created");
        refresh();

        startJob(NAME_PREFIX);
        waitJob(NAME_PREFIX);
        refresh();
    }

    @BeforeEach
    protected void init() {
        refresh();
    }

  for (int i = 0; i < num_tasks; i++) {
    int port = tensorflow::testing::PickUnusedPortOrDie();
    job_def->mutable_tasks()->insert({i, absl::StrCat("localhost:", port)});
    LOG(INFO) << "Picked test port: " << port << " for job: " << job_name
              << ", task: " << i;
  }
  return server_def;
}

tensorflow::ServerDef GetServerDef(int num_tasks) {
  return GetServerDef("localhost", num_tasks);
}

                logger.info("Start scheduler \"{}\"", schedulerId);
                return;
            }
            ThreadUtil.sleep(100L);
        }
        fail("could not start job.");
    }

    protected static void waitJob(final String namePrefix) {
        Boolean isRunning = false;
        int count = 0;
        long sleepTime = 50; // Start with 50ms

    .build();
MockWebServer server = new MockWebServer();
server.useHttps(serverCertificates.sslSocketFactory(), false);
```

`HandshakeCertificates` also works for clients where its job is to define which root certificates
to trust. In this simplified example we trust the server's self-signed certificate:

```java
HandshakeCertificates clientCertificates = new HandshakeCertificates.Builder()

 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and
 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash
 * function doing a good job of distributing the elements to the buckets to a distribution not far
 * from uniform), and amortized since some operations can trigger a hash table resize.
 *

  //
  //  Worker1:
  //  cluster { job { name: "client" tasks { key: 0 value: "localhost:14525" } }
  //            job { name: "worker" tasks { key: 1 value: "localhost:14523" } }
  //          } job_name: "worker" task_index: 1 protocol: "grpc"
  //
  //  Worker0:
  //  cluster { job { name: "client" tasks { key: 0 value: "localhost:14526" } }
  //            job { name: "worker" tasks { key: 0 value: "localhost:14522" } }

Creating and establishing new connections require a fair amount of overhead and added latency. OkHttp will make every effort to reuse existing connections to avoid this overhead and added latency.

Every OkHttpClient uses a connection pool. Its job is to maintain a reference to all open connections. When an HTTP request is started, OkHttp will attempt to reuse an existing connection from the pool. If there are no existing connections, a new one is created and put into the connection pool. For...

 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)
 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a
 * good job of distributing the elements to the buckets to a distribution not far from uniform), and
 * amortized since some operations can trigger a hash table resize.
 *