.listFiles()
        ?.associateWith { dir ->
            val dirPath = dir.toPath()
            Files.walk(dirPath).use { paths ->
                paths.filter { !it.toFile().isDirectory }
                    .limit(4)
                    .map { dirPath.relativize(it).toString() }
                    .collect(Collectors.toList())

The cashier gives you the number of your turn.

<img src="/img/async/concurrent-burgers/concurrent-burgers-04.png" class="illustration">

While you are waiting, you go with your crush and pick a table, you sit and talk with your crush for a long time (as your burgers are very fancy and take some time to prepare).

On the other side, there are thousands of users in the chat systems, so there's a high chance you'll find someone to talk to there, almost all the time. 😄

## Sponsor the author

You can also financially support the author (me) through <a href="https://github.com/sponsors/tiangolo" class="external-link" target="_blank">GitHub sponsors</a>.

        val rootDirFiles = projectDir.resolve("build").walk().toList()

        archiveFileNames.forEach { fileName ->
            assertTrue(rootDirFiles.any { it.name == fileName })
        }
    }

    private
    fun assertLeftoverFilesCleanedUpEventually(vararg leftoverFiles: String) {
        leftoverFiles.forEach {
            assertTrue(projectDir.resolve(it).walk().filter { it.isFile }.toList().isEmpty())
        }

And then, there would be another program (in some cases it's another program, in some cases it could be the same TLS Termination Proxy) that would talk to Let's Encrypt, and renew the certificate(s).

<img src="/img/deployment/https/https.svg">

The **TLS certificates** are **associated with a domain name**, not with an IP address.

set in the metadata with the timestamp of replication and ResetID. For saving iops, the objects which are re-replicated are not first set to `PENDING` state.

This is a slower operation that does not use replication queues and is designed to walk the namespace and replicate objects one at a time so as not to impede server load. Ideally, resync should not be initiated for multiple buckets simultaneously - progress of the syncing can be monitored by looking at `mc replicate resync status alias/bucket...

I'll show you some concrete examples in the next chapters.

---

Then the next concepts to consider are all about the program running your actual API (e.g. Uvicorn).

## Program and Process

We will talk a lot about the running "**process**", so it's useful to have clarity about what it means, and what's the difference with the word "**program**".

### What is a Program

When you pass the file to `fastapi run` it will detect automatically that it is a single file and not part of a package and will know how to import it and serve your FastAPI app. 😎

## Deployment Concepts

Let's talk again about some of the same [Deployment Concepts](concepts.md){.internal-link target=_blank} in terms of containers.

    The **FastAPI** specific code is as small as always.

## ORMs

**FastAPI** works with any database and any style of library to talk to the database.

A common pattern is to use an "ORM": an "object-relational mapping" library.

An ORM has tools to convert ("*map*") between *objects* in code and database tables ("*relations*").