Compression and Redis wire formats

Latest stable Based on Bluetape4k release 1.11.0

Compression-only serialization

RedisCompressSerializer accepts a ByteArray, compresses it, and restores it. It does not convert objects into a binary format.

val serializer = RedisCompressSerializer(Compressors.LZ4)
val compressed = serializer.serialize(payload)
val restored = serializer.deserialize(compressed)

Use it when another layer already emits bytes, such as Protobuf, images, or documents. Use a RedisBinarySerializer combination for application objects.

Available compressors

Compression-only singletons are Gzip, LZ4, Snappy, and Zstd. Binary combinations apply one of the same compressors after object serialization.

The compressor name is not embedded automatically. A value written with LZ4Fory cannot be identified and decoded as an older format by ZstdFory. Use a key prefix, cache name, or envelope header to identify the format.

Measure small payloads

Compression can reduce network and Redis memory while adding CPU and allocation. Headers and block overhead may make small values larger.

Measure representative workloads for:

compressed and uncompressed byte size
serialize/compress and decompress/deserialize latency
end-to-end command latency and application CPU
Redis memory and network throughput
the production payload-size distribution

Module tests prove round-trip correctness. They make no benchmark claim that one combination is faster.

Null and corrupted payloads

serialize(null) returns empty bytes, while deserialize(null) returns null. Keep this distinct from compressing a real empty byte array.

Truncated or mismatched payloads fail during decompression. Trying several compressors as fallback can hide corruption and drift. Record an explicit format version and observe the failure instead.

Manage deployment formats

Allocate a new key prefix or schema version.
Verify the new writer and reader together.
Test whether an old reader can see a new value during rolling deployment.
Add dual-read or an explicit migration if required.
Define TTL or deletion for the old keyspace.

A compressor change is a wire-format change even when the object serializer stays Fory.