Redis لما يقع: الـ persistence (RDB و AOF) والـ replication

#!/bin/bash
# 3 servers تجريبية: من غير persistence، و RDB، و AOF. ونموّتهم بالعافية (kill -9)
set -e
rm -rf lab && mkdir -p lab/none lab/rdb lab/aof

start() { redis-server --port $1 --dir lab/$2 --daemonize yes --pidfile "$PWD/lab/$2.pid" --logfile "$PWD/lab/$2.log" ${@:3}; sleep 0.3; }
crash() { kill -9 $(cat lab/$1.pid); sleep 0.3; }
fill() { for i in $(seq 1 100); do echo "SET key:$i $i"; done | redis-cli -p $1 > /dev/null; }

start 6381 none --save "" --appendonly no
start 6382 rdb --save "" --appendonly no
start 6383 aof --save "" --appendonly yes --appendfsync everysec

fill 6381; fill 6382; fill 6383
redis-cli -p 6382 SAVE > /dev/null           # snapshot يدوي (RDB)
for i in $(seq 101 150); do redis-cli -p 6382 SET key:$i $i > /dev/null; done   # بعد الـ snapshot
for i in $(seq 101 150); do redis-cli -p 6383 SET key:$i $i > /dev/null; done
sleep 1.2                                      # everysec: نستنى الـ fsync

crash none; crash rdb; crash aof
start 6381 none --save "" --appendonly no
start 6382 rdb --save "" --appendonly no
start 6383 aof --save "" --appendonly yes

echo "من غير persistence: $(redis-cli -p 6381 DBSIZE) key"
echo "RDB:                $(redis-cli -p 6382 DBSIZE) key (اللي بعد آخر snapshot ضاع)"
echo "AOF everysec:       $(redis-cli -p 6383 DBSIZE) key"
for p in 6381 6382 6383; do redis-cli -p $p SHUTDOWN NOSAVE > /dev/null 2>&1 || true; done

$ bash crash.sh
من غير persistence: 0 key
RDB:                100 key (اللي بعد آخر snapshot ضاع)
AOF everysec:       150 key

#!/bin/bash
# primary على 6391، و replica على 6392
set -e
rm -rf lab && mkdir -p lab/p lab/r
redis-server --port 6391 --dir lab/p --save "" --daemonize yes --logfile "$PWD/lab/p.log"
redis-server --port 6392 --dir lab/r --save "" --daemonize yes --logfile "$PWD/lab/r.log" --replicaof localhost 6391
# استنى لحد ما الـ replica تخلّص أول نسخة كاملة (full sync)
until redis-cli -p 6392 INFO replication | grep -q "master_link_status:up"; do sleep 0.1; done

redis-cli -p 6391 SET user:7 mona > /dev/null
sleep 0.2
echo "الـ replica شايفة: $(redis-cli -p 6392 GET user:7)"
echo "كتابة على الـ replica: $(redis-cli -p 6392 SET x 1 2>&1)"
redis-cli -p 6391 INFO replication | grep -E "^(role|connected_slaves)"

# WAIT: استنى لحد ما N replicas يأكّدوا (أو timeout)
redis-cli -p 6391 SET order:9 paid > /dev/null
echo "WAIT 1 replica: $(redis-cli -p 6391 WAIT 1 500)"

# failover يدوي: الـ primary مات، رقّي الـ replica
redis-cli -p 6391 SHUTDOWN NOSAVE > /dev/null 2>&1 || true
redis-cli -p 6392 REPLICAOF NO ONE > /dev/null
echo "بعد الترقية: role=$(redis-cli -p 6392 INFO replication | grep ^role | cut -d: -f2 | tr -d "\r") و order:9=$(redis-cli -p 6392 GET order:9)"
redis-cli -p 6392 SHUTDOWN NOSAVE > /dev/null 2>&1 || true

$ bash replication.sh
الـ replica شايفة: mona
كتابة على الـ replica: READONLY You can't write against a read only replica.
role:master
connected_slaves:1
WAIT 1 replica: 1
بعد الترقية: role=master و order:9=paid

#!/bin/bash
set -e
rm -rf lab && mkdir lab
run() { redis-server redis-sessions.conf --dir lab --daemonize yes --pidfile "$PWD/lab/s.pid" --logfile "$PWD/lab/s.log"; sleep 0.3; }
run
for i in $(seq 1 500); do echo "SET sess:$i data EX 3600"; done | redis-cli -p 6385 > /dev/null
sleep 1.2
kill -9 $(cat lab/s.pid); sleep 0.3
run
echo "DBSIZE: $(redis-cli -p 6385 DBSIZE)"
redis-cli -p 6385 CONFIG GET maxmemory-policy | tr '\n' ' '; echo
redis-cli -p 6385 SHUTDOWN NOSAVE > /dev/null 2>&1 || true

$ bash crash-test.sh
DBSIZE: 500
maxmemory-policy volatile-ttl

port 6385
appendonly yes
appendfsync everysec
save 300 10
maxmemory 64mb
maxmemory-policy volatile-ttl