---
title: TTL on RawKV
description: Time to Live
menu:
    "dev":
        parent: Features-dev
        weight: 3
        identifier: TTL on RawKV-dev
---

This page walks you through a simple demonstration of how to use TTL (Time To Live) on RawKV. TTL is a data clearing mechanism that automatically deletes data after a specified period of time. For example:

- If TTL is not used, the data written to TiKV will always exist in TiKV unless it is manually deleted.
- If TTL is used, and the TTL time of a key is set to one hour, the data of the key will be automatically deleted by TiKV after one hour.

## Prerequisites

Before you start, ensure that you have installed TiUP and jshell, and have downloaded the `tikv-client` JARS file according to [TiKV in 5 Minutes](../../tikv-in-5-minutes).

## Step 1: Config TiKV to enable TTL

TTL is disabled by default. To enable it, create a file `tikv.yaml` using the following configuration.

```yaml
[storage]
enable-ttl = true
```

## Step 2: Start TiKV Cluster

For this tutorial, only one TiKV node is needed, so the `tiup playground` command is used.

Show TiUP version:

```bash
tiup -v
```

version >= 1.5.2:

```bash
tiup playground --mode tikv-slim  --kv.config tikv.yaml
```

version < 1.5.2:

```bash
tiup playground --kv.config tikv.yaml
```

## Step 3: Write the code to test TTL

The following example shows how to verify the TTL works.

Save the following script to file `test_raw_ttl.java`.

```java
import java.util.*;
import org.tikv.common.TiConfiguration;
import org.tikv.common.TiSession;
import org.tikv.raw.RawKVClient;
import org.tikv.shade.com.google.protobuf.ByteString;

TiConfiguration conf = TiConfiguration.createRawDefault("127.0.0.1:2379");
TiSession session = TiSession.create(conf);
RawKVClient client = session.createRawClient();

// write (k1, v1) with ttl=30 seconds
client.put(ByteString.copyFromUtf8("k1"), ByteString.copyFromUtf8("v1"), 30);

// write (k2, v2) without ttl
client.put(ByteString.copyFromUtf8("k2"), ByteString.copyFromUtf8("v2"));

// get k1 & k2 resturns v1 & v2
System.out.println(client.batchGet(new ArrayList<ByteString>() {{
      add(ByteString.copyFromUtf8("k1"));
      add(ByteString.copyFromUtf8("k2"));
}}));

// sleep 30 seconds
System.out.println("Sleep 30 seconds.")
Thread.sleep(30000);

// get k1 & k2 returns v2
// k1's ttl is expired
System.out.println(client.batchGet(new ArrayList<ByteString>() {{
      add(ByteString.copyFromUtf8("k1"));
      add(ByteString.copyFromUtf8("k2"));
}}));
```

## Step 4: Run the code

```bash
jshell --class-path tikv-client-java.jar:slf4j-api.jar --startup test_raw_ttl.java

[key: "k1"
value: "v1"
, key: "k2"
value: "v2"
]
Sleep 30 seconds.
[key: "k2"
value: "v2"
]
```

After running the above code, you can find that `k1` is automatically deleted when its TTL has expired.