RedisIO (Apache Beam 2.58.0)

java.lang.Object
- org.apache.beam.sdk.io.redis.RedisIO

```
public class RedisIO
extends java.lang.Object
```
An IO to manipulate Redis key/value database.
Reading Redis key/value pairs

read() provides a source which returns a bounded PCollection containing key/value pairs as KV<String, String>.
To configure a Redis source, you have to provide Redis server hostname and port number. Optionally, you can provide a key pattern (to filter the keys). The following example illustrates how to configure a source:
```
 pipeline.apply(RedisIO.read()
   .withEndpoint("::1", 6379)
   .withKeyPattern("foo*"))

 
```
It's also possible to specify Redis authentication and connection timeout with the corresponding methods:
```
 pipeline.apply(RedisIO.read()
   .withEndpoint("::1", 6379)
   .withAuth("authPassword")
   .withTimeout(60000)
   .withKeyPattern("foo*"))

 
```
readKeyPatterns() can be used to request Redis server using input PCollection elements as key pattern (as String).
```
 pipeline.apply(...)
    // here we have a PCollection<String> with the key patterns
    .apply(RedisIO.readKeyPatterns().withEndpoint("::1", 6379))
   // here we have a PCollection<KV<String,String>>

 
```
Writing Redis key/value pairs

write() provides a sink to write key/value pairs represented as KV from an incoming PCollection.
To configure the target Redis server, you have to provide Redis server hostname and port number. The following example illustrates how to configure a sink:
```
 pipeline.apply(...)
   // here we a have a PCollection<String, String> with key/value pairs
   .apply(RedisIO.write().withEndpoint("::1", 6379))

 
```
Writing Redis Streams

writeStreams() appends the entries of a PCollection of key/value pairs represented as KV to the Redis stream at the specified key using the XADD API.
To configure the target Redis server, you have to provide a Redis server hostname and port number. The following example illustrates how to configure a sink:
```
 pipeline.apply(...)
   // here we have a PCollection<KV<String, Map<String, String>>>
   .apply(RedisIO.writeStreams().withEndpoint("::1", 6379))
 
```
Redis Streams optionally can be capped to a specific or exact length (see the documentation for the XTRIM API); writeStreams() lets you specify MAXLEN using the withMaxLen() option.
Trimming a stream to an exact length is noted in the Redis documentation as being inefficient; the withApproximateTrim() boolean option will add the ~ prefix to MAXLEN, which tells Redis to use "almost exact" trimming.
See the Redis Streams documentation for a deeper discussion of the issues involved.
The following example illustrates how to configure a sink with trimming:
```
 pipeline.apply(...)
   // here we have a PCollection<KV<String, Map<String, String>>>
   .apply(RedisIO.writeStreams()
     .withEndpoint("::1", 6379)
     .withMaxLen(1024L)
     .withApproximateTrim(true)
    )
 
```

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`RedisIO.Read` Implementation of `read()`.
`static class`	`RedisIO.ReadKeyPatterns` Implementation of `readKeyPatterns()`.
`static class`	`RedisIO.Write` A `PTransform` to write to a Redis server.
`static class`	`RedisIO.WriteStreams` A `PTransform` to write stream key pairs (https://redis.io/topics/streams-intro) to a Redis server.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static RedisIO.Read`	`read()` Read data from a Redis server.
`static RedisIO.ReadKeyPatterns`	`readKeyPatterns()` Like `read()` but executes multiple instances of the Redis query substituting each element of a `PCollection` as key pattern.
`static RedisIO.Write`	`write()` Write data to a Redis server.
`static RedisIO.WriteStreams`	`writeStreams()` Write stream data to a Redis server.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - read
```
public static RedisIO.Read read()
```
    Read data from a Redis server.
  - readKeyPatterns
```
public static RedisIO.ReadKeyPatterns readKeyPatterns()
```
    Like read() but executes multiple instances of the Redis query substituting each element of a PCollection as key pattern.
  - write
```
public static RedisIO.Write write()
```
    Write data to a Redis server.
  - writeStreams
```
public static RedisIO.WriteStreams writeStreams()
```
    Write stream data to a Redis server.

Class RedisIO

Reading Redis key/value pairs

Writing Redis key/value pairs

Writing Redis Streams

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

read

readKeyPatterns

write

writeStreams