rdb

This is a golang implemented Redis RDB parser for secondary development and memory analysis.

It provides abilities to:

• Generate memory report for rdb file
• Convert RDB files to JSON
• Convert RDB files to Redis Serialization Protocol (or AOF file)
• Find Biggest Key in RDB files
• Draw FlameGraph to analysis which kind of keys occupied most memory
• Customize data usage
• Generate RDB file

Thanks sripathikrishnan for his redis-rdb-tools

Install

If you have installed go on your compute, just simply use:

go get github.com/hdt3213/rdb

Or, you can download executable binary file from releases and put its path to PATH environment.

use rdb command in terminal, you can see it's manual

Convert to Json

Usage:

rdb -c json -o <output_path> <source_path>

example:

rdb -c json -o intset_16.json cases/intset_16.rdb

You can get some rdb examples in cases

The examples for json result:

[
    {"db":0,"key":"hash","size":64,"type":"hash","hash":{"ca32mbn2k3tp41iu":"ca32mbn2k3tp41iu","mddbhxnzsbklyp8c":"mddbhxnzsbklyp8c"}},
    {"db":0,"key":"string","size":10,"type":"string","value":"aaaaaaa"},
    {"db":0,"key":"expiration","expiration":"2022-02-18T06:15:29.18+08:00","size":8,"type":"string","value":"zxcvb"},
    {"db":0,"key":"list","expiration":"2022-02-18T06:15:29.18+08:00","size":66,"type":"list","values":["7fbn7xhcnu","lmproj6c2e","e5lom29act","yy3ux925do"]},
    {"db":0,"key":"zset","expiration":"2022-02-18T06:15:29.18+08:00","size":57,"type":"zset","entries":[{"member":"zn4ejjo4ths63irg","score":1},{"member":"1ik4jifkg6olxf5n","score":2}]},
    {"db":0,"key":"set","expiration":"2022-02-18T06:15:29.18+08:00","size":39,"type":"set","members":["2hzm5rnmkmwb3zqd","tdje6bk22c6ddlrw"]}
]

Generate Memory Report

RDB uses rdb encoded size to estimate redis memory usage.

rdb -c memory -o <output_path> <source_path>

Example:

rdb -c memory -o mem.csv cases/memory.rdb

The examples for csv result:

database,key,type,size,size_readable,element_count
0,hash,hash,64,64B,2
0,s,string,10,10B,0
0,e,string,8,8B,0
0,list,list,66,66B,4
0,zset,zset,57,57B,2
0,large,string,2056,2K,0
0,set,set,39,39B,2

Find Biggest Keys

RDB can find biggest N keys in file

rdb -c bigkey -n <result_number> <source_path>

Example:

rdb -c bigkey -n 5 cases/memory.rdb

The examples for csv result:

database,key,type,size,size_readable,element_count
0,large,string,2056,2K,0
0,list,list,66,66B,4
0,hash,hash,64,64B,2
0,zset,zset,57,57B,2
0,set,set,39,39B,2

Convert to AOF

Usage:

rdb -c aof -o <output_path> <source_path>

Example:

rdb -c aof -o mem.aof cases/memory.rdb

The examples for aof result:

*3
$3
SET
$1
s
$7
aaaaaaa

Flame Graph

In many cases there is not a few very large key but lots of small keys that occupied most memory.

RDB tool could separate keys by the given delimeters, then aggregate keys with same prefix.

Finally RDB tool presents the result as flame graph, with which you could find out which kind of keys consumed most memory.

In this example, the keys of pattern Comment:* use 8.463% memory.

Usage:

rdb -c flamegraph [-port <port>] [-sep <separator1>] [-sep <separator2>] <source_path>

Example:

rdb -c flamegraph -port 16379 -sep : dump.rdb

Regex Filter

RDB tool supports using regex expression to filter keys.

Example:

rdb -c json -o regex.json -regex '^l.*' cases/memory.rdb

Customize data usage

package main

import (
	"github.com/hdt3213/rdb/parser"
	"os"
)

func main() {
	rdbFile, err := os.Open("dump.rdb")
	if err != nil {
		panic("open dump.rdb failed")
	}
	defer func() {
		_ = rdbFile.Close()
	}()
	decoder := parser.NewDecoder(rdbFile)
	err = decoder.Parse(func(o parser.RedisObject) bool {
		switch o.GetType() {
		case parser.StringType:
			str := o.(*parser.StringObject)
			println(str.Key, str.Value)
		case parser.ListType:
			list := o.(*parser.ListObject)
			println(list.Key, list.Values)
		case parser.HashType:
			hash := o.(*parser.HashObject)
			println(hash.Key, hash.Hash)
		case parser.ZSetType:
			zset := o.(*parser.ZSetObject)
			println(zset.Key, zset.Entries)
		}
		// return true to continue, return false to stop the iteration
		return true
	})
	if err != nil {
		panic(err)
	}
}

Generate RDB file

This library can generate RDB file:

package main

import (
	"github.com/hdt3213/rdb/encoder"
	"github.com/hdt3213/rdb/model"
	"os"
	"time"
)

func main() {
	rdbFile, err := os.Create("dump.rdb")
	if err != nil {
		panic(err)
	}
	defer rdbFile.Close()
	enc := encoder.NewEncoder(rdbFile)
	err = enc.WriteHeader()
	if err != nil {
		panic(err)
	}
	auxMap := map[string]string{
		"redis-ver":    "4.0.6",
		"redis-bits":   "64",
		"aof-preamble": "0",
	}
	for k, v := range auxMap {
		err = enc.WriteAux(k, v)
		if err != nil {
			panic(err)
		}
	}

	err = enc.WriteDBHeader(0, 5, 1)
	if err != nil {
		panic(err)
	}
	expirationMs := uint64(time.Now().Add(time.Hour*8).Unix() * 1000)
	err = enc.WriteStringObject("hello", []byte("world"), encoder.WithTTL(expirationMs))
	if err != nil {
		panic(err)
	}
	err = enc.WriteListObject("list", [][]byte{
		[]byte("123"),
		[]byte("abc"),
		[]byte("la la la"),
	})
	if err != nil {
		panic(err)
	}
	err = enc.WriteSetObject("set", [][]byte{
		[]byte("123"),
		[]byte("abc"),
		[]byte("la la la"),
	})
	if err != nil {
		panic(err)
	}
	err = enc.WriteHashMapObject("list", map[string][]byte{
		"1":  []byte("123"),
		"a":  []byte("abc"),
		"la": []byte("la la la"),
	})
	if err != nil {
		panic(err)
	}
	err = enc.WriteZSetObject("list", []*model.ZSetEntry{
		{
			Score: 1.234,
			Member: "a",
		},
		{
			Score: 2.71828,
			Member: "b",
		},
	})
	if err != nil {
		panic(err)
	}
	err = enc.WriteEnd()
	if err != nil {
		panic(err)
	}
}