Hi, We get this error when redis execute BGSAVE, Any idea why this happens and how to fix it?
Redis Version: Redis server v=6.0.16 sha=00000000:0 malloc=jemalloc-5.1.0 bits=64 build=f7b6ec69a8fa9847
Environment: Kubernetes Cluster
Redis Cluster: Sentinel failover cluster with 9 redis slaves and 3 sentinel pods
1:M 26 Jun 2023 07:43:43.115 * Replica 10.0.18.27:6379 asks for synchronization
1:M 26 Jun 2023 07:43:43.115 * Full resync requested by replica 10.0.18.27:6379
1:M 26 Jun 2023 07:43:43.115 * Starting BGSAVE for SYNC with target: disk
1:M 26 Jun 2023 07:43:43.284 * Background saving started by pid 445418
1:M 26 Jun 2023 07:43:43.285 # Warning, detected child with unmatched pid: 331103
1:M 26 Jun 2023 07:43:43.386 # Warning, detected child with unmatched pid: 331104
1:M 26 Jun 2023 07:43:43.487 # Warning, detected child with unmatched pid: 331105
1:M 26 Jun 2023 07:43:43.587 # Warning, detected child with unmatched pid: 331106
1:M 26 Jun 2023 07:43:43.688 # Warning, detected child with unmatched pid: 331107
1:M 26 Jun 2023 07:43:43.788 # Warning, detected child with unmatched pid: 331100
1:M 26 Jun 2023 07:43:43.890 # Warning, detected child with unmatched pid: 331102
1:M 26 Jun 2023 07:43:43.990 # Warning, detected child with unmatched pid: 331125
1:M 26 Jun 2023 07:43:44.090 # Warning, detected child with unmatched pid: 331126
1:M 26 Jun 2023 07:43:44.190 # Warning, detected child with unmatched pid: 331127
1:M 26 Jun 2023 07:43:44.291 # Warning, detected child with unmatched pid: 331128
1:M 26 Jun 2023 07:43:44.391 # Warning, detected child with unmatched pid: 331123
1:M 26 Jun 2023 07:43:44.491 # Warning, detected child with unmatched pid: 331121
1:M 26 Jun 2023 07:43:44.591 # Warning, detected child with unmatched pid: 331124
1:M 26 Jun 2023 07:43:44.692 # Warning, detected child with unmatched pid: 331147
1:M 26 Jun 2023 07:43:44.796 # Warning, detected child with unmatched pid: 331148
1:M 26 Jun 2023 07:43:44.896 # Warning, detected child with unmatched pid: 331149
1:M 26 Jun 2023 07:43:44.996 # Warning, detected child with unmatched pid: 331150
1:M 26 Jun 2023 07:43:45.096 # Warning, detected child with unmatched pid: 331145
1:M 26 Jun 2023 07:43:45.196 # Warning, detected child with unmatched pid: 331143
1:M 26 Jun 2023 07:43:45.296 # Warning, detected child with unmatched pid: 472277
1:M 26 Jun 2023 07:43:45.401 # Warning, detected child with unmatched pid: 472278
1:M 26 Jun 2023 07:43:45.504 # Warning, detected child with unmatched pid: 472279
1:M 26 Jun 2023 07:43:45.604 # Warning, detected child with unmatched pid: 472280
1:M 26 Jun 2023 07:43:45.705 # Warning, detected child with unmatched pid: 472276
1:M 26 Jun 2023 07:43:46.274 # Warning, detected child with unmatched pid: 472273
1:M 26 Jun 2023 07:43:46.375 # Warning, detected child with unmatched pid: 472299
1:M 26 Jun 2023 07:43:46.475 # Warning, detected child with unmatched pid: 472300
1:M 26 Jun 2023 07:43:46.575 # Warning, detected child with unmatched pid: 472301
1:M 26 Jun 2023 07:43:46.675 # Warning, detected child with unmatched pid: 472302
1:M 26 Jun 2023 07:43:46.775 # Warning, detected child with unmatched pid: 472298
1:M 26 Jun 2023 07:43:46.875 # Warning, detected child with unmatched pid: 472297
1:M 26 Jun 2023 07:43:46.976 # Warning, detected child with unmatched pid: 472295
1:M 26 Jun 2023 07:43:47.076 # Warning, detected child with unmatched pid: 472322
1:M 26 Jun 2023 07:43:47.177 # Warning, detected child with unmatched pid: 472323
1:M 26 Jun 2023 07:43:47.277 # Warning, detected child with unmatched pid: 472324
1:M 26 Jun 2023 07:43:47.377 # Warning, detected child with unmatched pid: 472325
1:M 26 Jun 2023 07:43:47.477 # Warning, detected child with unmatched pid: 472321
1:M 26 Jun 2023 07:43:47.577 # Warning, detected child with unmatched pid: 472320
1:M 26 Jun 2023 07:43:47.678 # Warning, detected child with unmatched pid: 472318
1:M 26 Jun 2023 07:43:47.779 # Warning, detected child with unmatched pid: 472335
1:M 26 Jun 2023 07:43:47.880 # Warning, detected child with unmatched pid: 472337
1:M 26 Jun 2023 07:43:47.980 # Warning, detected child with unmatched pid: 472338
1:M 26 Jun 2023 07:43:48.080 # Warning, detected child with unmatched pid: 472339
1:M 26 Jun 2023 07:43:48.180 # Warning, detected child with unmatched pid: 472340
1:M 26 Jun 2023 07:43:48.280 # Warning, detected child with unmatched pid: 472333
1:M 26 Jun 2023 07:43:48.380 # Warning, detected child with unmatched pid: 472348
1:M 26 Jun 2023 07:43:48.481 # Warning, detected child with unmatched pid: 472351
1:M 26 Jun 2023 07:43:48.581 # Warning, detected child with unmatched pid: 472352
1:M 26 Jun 2023 07:43:48.682 # Warning, detected child with unmatched pid: 472353
1:M 26 Jun 2023 07:43:48.782 # Warning, detected child with unmatched pid: 472355
1:M 26 Jun 2023 07:43:48.882 # Warning, detected child with unmatched pid: 778503
1:M 26 Jun 2023 07:43:48.982 # Warning, detected child with unmatched pid: 778501
1:M 26 Jun 2023 07:43:49.083 # Warning, detected child with unmatched pid: 778504
1:M 26 Jun 2023 07:43:49.183 # Warning, detected child with unmatched pid: 778505
1:M 26 Jun 2023 07:43:49.283 # Warning, detected child with unmatched pid: 778506
1:M 26 Jun 2023 07:43:49.383 # Warning, detected child with unmatched pid: 778507
1:M 26 Jun 2023 07:43:49.483 # Warning, detected child with unmatched pid: 778508
1:M 26 Jun 2023 07:43:49.583 # Warning, detected child with unmatched pid: 778524
1:M 26 Jun 2023 07:43:49.684 # Warning, detected child with unmatched pid: 778522
1:M 26 Jun 2023 07:43:49.784 # Warning, detected child with unmatched pid: 778525
1:M 26 Jun 2023 07:43:49.884 # Warning, detected child with unmatched pid: 778526
1:M 26 Jun 2023 07:43:49.984 # Warning, detected child with unmatched pid: 778527
1:M 26 Jun 2023 07:43:50.093 # Warning, detected child with unmatched pid: 778528
1:M 26 Jun 2023 07:43:50.193 # Warning, detected child with unmatched pid: 778549
1:M 26 Jun 2023 07:43:50.298 # Warning, detected child with unmatched pid: 778550
1:M 26 Jun 2023 07:43:50.398 # Warning, detected child with unmatched pid: 778551
1:M 26 Jun 2023 07:43:50.498 # Warning, detected child with unmatched pid: 778552
1:M 26 Jun 2023 07:43:50.598 # Warning, detected child with unmatched pid: 778548
1:M 26 Jun 2023 07:43:50.700 # Warning, detected child with unmatched pid: 778545
1:M 26 Jun 2023 07:43:50.812 # Warning, detected child with unmatched pid: 788418
1:M 26 Jun 2023 07:43:50.912 # Warning, detected child with unmatched pid: 788419
1:M 26 Jun 2023 07:43:51.012 # Warning, detected child with unmatched pid: 788420
1:M 26 Jun 2023 07:43:51.113 # Warning, detected child with unmatched pid: 788422
1:M 26 Jun 2023 07:43:51.213 # Warning, detected child with unmatched pid: 788423
1:M 26 Jun 2023 07:43:51.316 # Warning, detected child with unmatched pid: 788416
1:M 26 Jun 2023 07:43:51.416 # Warning, detected child with unmatched pid: 788434
1:M 26 Jun 2023 07:43:51.516 # Warning, detected child with unmatched pid: 788432
1:M 26 Jun 2023 07:43:51.616 # Warning, detected child with unmatched pid: 788436
1:M 26 Jun 2023 07:43:51.716 # Warning, detected child with unmatched pid: 788437
1:M 26 Jun 2023 07:43:51.816 # Warning, detected child with unmatched pid: 788438
1:M 26 Jun 2023 07:43:51.916 # Warning, detected child with unmatched pid: 788456
1:M 26 Jun 2023 07:43:52.016 # Warning, detected child with unmatched pid: 788461
1:M 26 Jun 2023 07:43:52.117 # Warning, detected child with unmatched pid: 788462
1:M 26 Jun 2023 07:43:52.218 # Warning, detected child with unmatched pid: 788463
1:M 26 Jun 2023 07:43:52.318 # Warning, detected child with unmatched pid: 788459
1:M 26 Jun 2023 07:43:52.418 # Warning, detected child with unmatched pid: 788475
1:M 26 Jun 2023 07:43:52.519 # Warning, detected child with unmatched pid: 788477
1:M 26 Jun 2023 07:43:52.619 # Warning, detected child with unmatched pid: 788478
1:M 26 Jun 2023 07:43:52.720 # Warning, detected child with unmatched pid: 788479
1:M 26 Jun 2023 07:43:52.820 # Warning, detected child with unmatched pid: 788472
1:M 26 Jun 2023 07:43:52.921 # Warning, detected child with unmatched pid: 906119
1:M 26 Jun 2023 07:43:53.022 # Warning, detected child with unmatched pid: 906118
1:M 26 Jun 2023 07:43:53.080 * Replica 10.0.55.194:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.080 * Full resync requested by replica 10.0.55.194:6379
1:M 26 Jun 2023 07:43:53.081 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.122 # Warning, detected child with unmatched pid: 906116
1:M 26 Jun 2023 07:43:53.175 * Replica 10.0.1.75:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.175 * Full resync requested by replica 10.0.1.75:6379
1:M 26 Jun 2023 07:43:53.176 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.222 # Warning, detected child with unmatched pid: 906120
1:M 26 Jun 2023 07:43:53.304 * Replica 10.0.60.78:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.304 * Full resync requested by replica 10.0.60.78:6379
1:M 26 Jun 2023 07:43:53.305 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.322 # Warning, detected child with unmatched pid: 906122
1:M 26 Jun 2023 07:43:53.424 # Warning, detected child with unmatched pid: 906123
1:M 26 Jun 2023 07:43:53.524 # Warning, detected child with unmatched pid: 906135
1:M 26 Jun 2023 07:43:53.569 * Replica 10.0.33.249:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.569 * Full resync requested by replica 10.0.33.249:6379
1:M 26 Jun 2023 07:43:53.570 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.617 * Replica 10.0.53.126:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.617 * Full resync requested by replica 10.0.53.126:6379
1:M 26 Jun 2023 07:43:53.618 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.624 # Warning, detected child with unmatched pid: 906136
1:M 26 Jun 2023 07:43:53.725 # Warning, detected child with unmatched pid: 906137
1:M 26 Jun 2023 07:43:53.746 * Replica 10.0.28.185:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.746 * Full resync requested by replica 10.0.28.185:6379
1:M 26 Jun 2023 07:43:53.748 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.826 # Warning, detected child with unmatched pid: 906138
1:M 26 Jun 2023 07:43:53.866 * Replica 10.0.38.185:6379 asks for synchronization
1:M 26 Jun 2023 07:43:53.866 * Full resync requested by replica 10.0.38.185:6379
1:M 26 Jun 2023 07:43:53.868 * Waiting for end of BGSAVE for SYNC
1:M 26 Jun 2023 07:43:53.927 # Warning, detected child with unmatched pid: 906131
1:M 26 Jun 2023 07:43:54.027 # Warning, detected child with unmatched pid: 906133
Comment From: moticless
Hi, I have failed to reproduce it with 6.0.16. I guess you are using bitnami Redis. If that is the case, then please raise this issue there for a start.
Comment From: tabrizu891
@moticless Hi, Actually I'm using Spotahome Redis. In this case I will raise issue there. THANK YOU.
Comment From: oranagra
i'm guessing it's related to a module doing fork() behind redis's back. (instead of using RM_Fork).
let us know if that's not the case.