.withRootDirectory(invokerRequest.rootDirectory().orElse(null))
                .build();
    }

    public Logger logger;

    // this one "evolves" as process progresses (instance is immutable but instances are replaced)
    public ProtoSession protoSession;
    // here we track which user properties we pushed to Java System Properties (internal only)
    public Set<String> pushedUserProperties;

/**
 * A non-blocking interface to a web socket. Use the [factory][WebSocket.Factory] to create
 * instances; usually this is [OkHttpClient].
 *
 * ## Web Socket Lifecycle
 *
 * Upon normal operation each web socket progresses through a sequence of states:
 *
 *  * **Connecting:** the initial state of each web socket. Messages may be enqueued but they won't
 *    be transmitted until the web socket is open.
 *

is added to the map.
Conversely, when comparing types, a known type argument
(a type argument for which a map entry already exists)
takes the place of its corresponding type parameter.
As type inference progresses, the map is populated more and more
until all equations have been considered, or until unification fails.
Type inference succeeds if no unification step fails and the map has
an entry for each type parameter.
</p>

import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;

/**
 * Helper class for managing data crawling operations in Fess.
 * This class coordinates the execution of data store crawling processes,
 * managing multiple concurrent crawling threads and handling the indexing
 * of crawled documents into the search engine.
 *
 * <p>The DataIndexHelper supports:</p>
 * <ul>

     * Continuously processes crawled documents from the data service, transforms them,
     * and updates the search index until crawling is finished and all documents are processed.
     *
     * <p>The method performs the following operations in a loop:
     * <ul>
     * <li>Retrieves access results from the data service</li>
     * <li>Processes each document through transformers</li>

* Others...

## Replication - Processes and Memory { #replication-processes-and-memory }

With a FastAPI application, using a server program like the `fastapi` command that runs Uvicorn, running it once in **one process** can serve multiple clients concurrently.

But in many cases, you will want to run several worker processes at the same time.

### Multiple Processes - Workers { #multiple-processes-workers }

    margin-bottom: 0.75rem;
}

.progress-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.5rem;
    min-width: 70px;
    opacity: 0.4;
    transition: all 0.3s ease;
}

.progress-step.active {
    opacity: 1;
}

.progress-step.completed {
    opacity: 0.7;
}

.progress-step .step-icon {
    width: 32px;
    height: 32px;

import org.codelibs.fess.util.JobProcess;

import jakarta.annotation.PreDestroy;

/**
 * Helper class for managing system processes in Fess.
 * This class provides functionality to start, stop, and manage external processes
 * such as crawler processes, with proper resource cleanup and lifecycle management.
 */
public class ProcessHelper {
    /** Logger instance for this class */

* Restarts
* **Replication (the number of processes running)**
* Memory
* Previous steps before starting

Up to this point, with all the tutorials in the docs, you have probably been running a **server program**, for example, using the `fastapi` command, that runs Uvicorn, running a **single process**.

        try {
            // Start multiple processes
            processHelper.startProcess(sessionId1, cmdList, pbCall);
            processHelper.startProcess(sessionId2, cmdList, pbCall);

            assertTrue(processHelper.isProcessRunning());

            // Wait a bit for the processes to start
            Thread.sleep(50);

            // Destroy all processes
            processHelper.destroy();