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redis超过内存大小是否会挂?

news 来源：原创 2024/9/20 5:28:43

redis超过内存大小是否会挂

前提条件：appendonly yes

好奇这个问题，所以做了个实验。答案是会挂掉的，并且数据完全持久化。

容量达到限制之后，内存溢出，Redis服务会挂掉。但是重启redis可以发现，实际落库持久化的并执行了db13:keys=420,expires=0,avg_ttl=0db13:keys=420,expires=0,avg_ttl=0程序日志可以看出执行到这里开始挂掉，完全持久化成功。那redis的持久化策略是啥呢？

模拟插入大数据量

package icu.kevin.cache.avalanche;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.scheduling.annotation.Async;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;import java.util.Random;@Slf4j
@RequestMapping("large")
@RestController
public class LargeKeyController {@Autowiredprivate RedisTemplate redisTemplate;@GetMapping("init")@Asyncpublic void initData(@RequestParam (name = "size", defaultValue = "5000") Integer size){log.info("starting init size........." + size);for (int i = 0; i < size; i++) {log.info("starting init data........." + i);redisTemplate.opsForSet().add("large_key_" + i, generateTestData(10 * 1024));}}public static String generateTestData(int sizeInKb) {int length = sizeInKb * 1024;int chunkSize = 10;int chunks = length / chunkSize;StringBuilder sb = new StringBuilder(length);for (int i = 0; i < chunks; i++) {String chunk = generateRandomString(chunkSize);sb.append(chunk);}return sb.toString();}public static String generateRandomString(int length) {String characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";StringBuilder sb = new StringBuilder(length);Random random = new Random();for (int i = 0; i < length; i++) {int index = random.nextInt(characters.length());sb.append(characters.charAt(index));}return sb.toString();}}

容量达到限制之后，内存溢出，Redis服务会挂掉

=== REDIS BUG REPORT START: Cut & paste starting from here ===
[28204] 07 Aug 10:57:51.458 # Redis version: 3.0.504
[28204] 07 Aug 10:57:51.459 # --- EXCEPTION_ACCESS_VIOLATION
[28204] 07 Aug 10:57:51.460 # --- STACK TRACE
redis-server.exe!LogStackTrace(c:\release\redis\src\win32_interop\win32_stacktrace.cpp:95)(0x00FBE580, 0x00FBFF60, 0x40028E60, 0x40124730)
。。。。。。。。。。。。。。。。。。。。
[28204] 07 Aug 10:57:51.488 # --- INFO OUTPUT
# Server
redis_version:3.0.504
redis_git_sha1:00000000
redis_git_dirty:0
redis_build_id:a4f7a6e86f2d60b3
redis_mode:standalone
os:Windows
arch_bits:64
multiplexing_api:WinSock_IOCP
process_id:28204
run_id:56302233dfa6c8a9a5ce3804c5638c3415c8d668
tcp_port:6379
uptime_in_seconds:139
uptime_in_days:0
hz:10
lru_clock:11723439
config_file:D:\Program Files\Redis\redis.windows-service.conf# Clients
connected_clients:2
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0# Memory
used_memory:5386539784
used_memory_human:5.02G
used_memory_rss:5386481064
used_memory_peak:5386539784
used_memory_peak_human:5.02G
used_memory_lua:36864
mem_fragmentation_ratio:1.00
mem_allocator:jemalloc-3.6.0# Persistence
loading:0
rdb_changes_since_last_save:417
rdb_bgsave_in_progress:0
rdb_last_save_time:1722999332
rdb_last_bgsave_status:ok
rdb_last_bgsave_time_sec:-1
rdb_current_bgsave_time_sec:-1
aof_enabled:0
aof_rewrite_in_progress:0
aof_rewrite_scheduled:0
aof_last_rewrite_time_sec:-1
aof_current_rewrite_time_sec:-1
aof_last_bgrewrite_status:ok
aof_last_write_status:ok# Stats
total_connections_received:420
total_commands_processed:841
instantaneous_ops_per_sec:6
total_net_input_bytes:4372605821
total_net_output_bytes:8298
instantaneous_input_kbps:34863.84
instantaneous_output_kbps:0.05
rejected_connections:0
sync_full:0
sync_partial_ok:0
sync_partial_err:0
expired_keys:0
evicted_keys:0
keyspace_hits:0
keyspace_misses:0
pubsub_channels:0
pubsub_patterns:0
latest_fork_usec:0
migrate_cached_sockets:0# Replication
role:master
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0# CPU
used_cpu_sys:7.17
used_cpu_user:4.48
used_cpu_sys_children:0.00
used_cpu_user_children:0.00# Commandstats
cmdstat_sadd:calls=417,usec=1579622,usec_per_call=3788.06
cmdstat_select:calls=419,usec=2190,usec_per_call=5.23
cmdstat_scan:calls=1,usec=34,usec_per_call=34.00
cmdstat_ping:calls=3,usec=16,usec_per_call=5.33
cmdstat_info:calls=1,usec=107,usec_per_call=107.00# Cluster
cluster_enabled:0# Keyspace
db0:keys=21,expires=0,avg_ttl=0
db10:keys=4,expires=0,avg_ttl=0
db13:keys=420,expires=0,avg_ttl=0
[28204] 07 Aug 10:57:51.489 #
=== REDIS BUG REPORT END. Make sure to include from START to END. ===