# Add KeyDB repository
curl -fsSL https://download.keydb.dev/pkg/open_source/gpg | sudo gpg --dearmor -o /usr/share/keyrings/keydb.gpg

echo "deb [signed-by=/usr/share/keyrings/keydb.gpg] https://download.keydb.dev/pkg/open_source/deb $(lsb_release -cs) main" \
  | sudo tee /etc/apt/sources.list.d/keydb.list

sudo apt update
sudo apt install -y keydb

# Enable and start
sudo systemctl enable keydb-server
sudo systemctl start keydb-server

# Verify installation
keydb-cli ping
# PONG

keydb-cli info server | grep -E "keydb_version|redis_version"

# Add KeyDB repository
sudo rpm --import https://download.keydb.dev/pkg/open_source/gpg
cat > /etc/yum.repos.d/keydb.repo << 'EOF'
[keydb]
name=KeyDB
baseurl=https://download.keydb.dev/pkg/open_source/rpm/el$releasever/$basearch
enabled=1
gpgcheck=1
gpgkey=https://download.keydb.dev/pkg/open_source/gpg
EOF

sudo dnf install -y keydb
sudo systemctl enable --now keydb-server

# Download the latest KeyDB binary
wget https://github.com/Snapchat/KeyDB/releases/latest/download/keydb-latest-linux-x86_64.tar.gz
tar -xzf keydb-latest-linux-x86_64.tar.gz
sudo cp keydb/keydb-server keydb/keydb-cli /usr/local/bin/

# Main config file location
sudo nano /etc/keydb/keydb.conf

# /etc/keydb/keydb.conf

# Bind address
bind 127.0.0.1
port 6379

# Require password
requirepass your-strong-password-here

# Max memory
maxmemory 1gb
maxmemory-policy allkeys-lru

# Persistence
save 900 1
save 300 10
save 60 10000

appendonly yes
appendfilename "appendonly.aof"
appendfsync everysec

# Log level
loglevel notice
logfile /var/log/keydb/keydb-server.log

# Data directory
dir /var/lib/keydb

sudo systemctl restart keydb-server

# Test with password
keydb-cli -a your-strong-password-here ping

# /etc/keydb/keydb.conf

# Enable server threads (set to number of CPU cores)
# Use 'nproc' to find your CPU count
server-threads 4

# Thread multiplexing (allows threads to share connections)
server-thread-affinity true

# Background threads for I/O operations
io-threads 4
io-threads-do-reads yes

# Check CPU cores
nproc

# Benchmark comparison: KeyDB vs Redis
# Run with KeyDB
keydb-benchmark -a your-password -c 50 -n 100000 -q

# For comparison (if Redis is on a different port):
# redis-benchmark -p 6380 -c 50 -n 100000 -q

# Check server thread stats
keydb-cli -a your-password info keydb | grep -i thread

# Node 1 configuration (/etc/keydb/keydb.conf on server1)
bind 0.0.0.0
port 6379
requirepass replicationpassword
masterauth replicationpassword

# Point to peer node (active replication)
replicaof 192.168.1.2 6379

# Allow writes on all nodes (active replication mode)
active-replica yes
multi-master yes

# Node 2 configuration (/etc/keydb/keydb.conf on server2)
bind 0.0.0.0
port 6379
requirepass replicationpassword
masterauth replicationpassword

replicaof 192.168.1.1 6379
active-replica yes
multi-master yes

# Restart both nodes
sudo systemctl restart keydb-server

# Verify active replication on Node 1
keydb-cli -a replicationpassword info replication

# Write on Node 1
keydb-cli -a replicationpassword set testkey "from-node1"

# Read from Node 2 - should return "from-node1"
keydb-cli -h 192.168.1.2 -a replicationpassword get testkey

# Install KeyDB with FLASH support
# Flash support may require the enterprise edition or specific build
# Check: keydb-server --version | grep flash

# Configure FLASH in keydb.conf

# /etc/keydb/keydb.conf

# Enable FLASH storage
# Requires KeyDB Pro or a FLASH-enabled build
storage-provider flash /mnt/keydb-flash

# Max memory in RAM (hot data)
maxmemory 2gb
maxmemory-policy allkeys-lru

# FLASH stores the rest (configure mount point on fast SSD)

# Prepare NVMe mount for FLASH
sudo mkfs.ext4 /dev/nvme0n1p1
sudo mkdir -p /mnt/keydb-flash
sudo mount /dev/nvme0n1p1 /mnt/keydb-flash
sudo chown keydb:keydb /mnt/keydb-flash

# Add to /etc/fstab for persistence
echo "/dev/nvme0n1p1 /mnt/keydb-flash ext4 defaults,noatime 0 2" | sudo tee -a /etc/fstab

sudo systemctl restart keydb-server

# Any Redis client works with KeyDB
# Python example
pip install redis

python3 << 'EOF'
import redis

# Connect to KeyDB exactly as you would to Redis
r = redis.Redis(host='localhost', port=6379, password='your-password', decode_responses=True)

r.set('key', 'value')
print(r.get('key'))  # value

r.lpush('mylist', 'a', 'b', 'c')
print(r.lrange('mylist', 0, -1))  # ['c', 'b', 'a']

r.hset('myhash', 'field1', 'value1')
print(r.hgetall('myhash'))  # {'field1': 'value1'}
EOF

# Node.js with ioredis
npm install ioredis
node -e "
const Redis = require('ioredis');
const client = new Redis({ host: 'localhost', port: 6379, password: 'your-password' });
client.set('foo', 'bar').then(() => client.get('foo')).then(v => { console.log(v); client.quit(); });
"

# Method 1: Redis DUMP/RESTORE - for individual keys
# Method 2: RDB file migration (fastest for full datasets)

# Step 1: Create an RDB snapshot on the Redis server
redis-cli -p 6380 BGSAVE
# Wait for save to complete
redis-cli -p 6380 LASTSAVE

# Step 2: Copy the RDB file to KeyDB server
scp /var/lib/redis/dump.rdb user@keydb-server:/var/lib/keydb/dump.rdb
sudo chown keydb:keydb /var/lib/keydb/dump.rdb

# Step 3: Stop KeyDB, replace data, restart
sudo systemctl stop keydb-server
sudo cp /var/lib/keydb/dump.rdb /var/lib/keydb/dump.rdb.bak
sudo systemctl start keydb-server

# Verify data is loaded
keydb-cli -a your-password dbsize
# Should match original Redis dbsize

# Method 3: Live replication migration
# Configure KeyDB to replicate from existing Redis temporarily
# In keydb.conf:
# replicaof <redis-host> 6379
# Let it sync, then remove the replicaof directive
# keydb-cli replicaof NO ONE

# Check if Redis is running on the same port
ss -tlnp | grep 6379
sudo systemctl stop redis-server

# Or change KeyDB port
# In keydb.conf: port 6380

# Check actual memory usage
keydb-cli -a password info memory | grep -E "used_memory_human|maxmemory"

# Reduce maxmemory or increase system RAM
# Set proper eviction policy
keydb-cli -a password config set maxmemory-policy allkeys-lru

# Check replication status on both nodes
keydb-cli -a password info replication

# Force a full resync
keydb-cli -a password replicaof NO ONE
keydb-cli -a password replicaof 192.168.1.2 6379

# Verify multi-threading is active
keydb-cli -a password info keydb | grep server_thread

# Check if server-threads is > 1 in config
keydb-cli -a password config get server-threads

# Run benchmark to confirm
keydb-benchmark -a password -c 100 -n 1000000 --threads 4 -q