# flush()

This operation flushes the streaming data onto the disk and seals the current segment.

```java
public void flush(FlushReq request)
```

## Request Syntax

```java
flush(FlushReq.builder()
    .collectionNames(List<String>)
    .waitFlushedTimeoutMs(Long)
    .build()
)
```

**BUILDER METHODS:**

- `collectionNames(List<String>)`

    The names of the the target collections.

- `waitFlushedTimeoutMs(Long)`

    The timeout duration for the current operation in milliseconds.

**RETURN TYPE:**

*void*

**RETURNS:**

N/A

## Example

```java
import io.milvus.v2.client.ConnectConfig;
import io.milvus.v2.client.MilvusClientV2;
import io.milvus.v2.service.utility.request.FlushReq;

// 1. Set up a client
ConnectConfig connectConfig = ConnectConfig.builder()
        .uri("http://localhost:19530")
        .token("root:Milvus")
        .build();
        
MilvusClientV2 client = new MilvusClientV2(connectConfig);

// 2. Compact a collection
client.flush(FlushReq.builder()
    .collectionNames(Collections.singletonList("my_collection"))
    .build();
);
```