Ceph » rgw

we have a two-zone multi-site setup, zone lvs and zone slc respectively. It works fine in general however we got reports from customer about data corruption/mismatch between two zone

root@host:~# s3cmd -c .s3cfg_lvs ls s3://ms-nsn-prod-48/01DAT9KVPEDE4QTA6EWFBZJ5KS/index
2019-05-14 04:30 410444223 s3://ms-nsn-prod-48/01DAT9KVPEDE4QTA6EWFBZJ5KS/index
root@host-ump:~# s3cmd -c .s3cfg_slc ls s3://ms-nsn-prod-48/01DAT9KVPEDE4QTA6EWFBZJ5KS/index
2019-05-14 04:30 62158776 s3://ms-nsn-prod-48/01DAT9KVPEDE4QTA6EWFBZJ5KS/index

Object metadata in SLC/LVS can be found in
https://pastebin.com/a5JNb9vb LVS
https://pastebin.com/1MuPJ0k1 SLC

SLC is a single flat object while LVS is a multi-part object, which indicate the object was uploaded by user in LVS and mirrored to SLC.The SLC object get truncated after 62158776, the first 62158776 bytes are right.

root@host:~# cmp -l slc_obj lvs_obj
cmp: EOF on slc_obj after byte 62158776

Both bucket sync status and overall sync status shows positive, and the obj was created 5 days ago. It sounds more like when pulling the object content from source zone(LVS), the transaction was terminated somewhere in between and cause an incomplete obj, and seems we dont have checksum verification in sync_agent so that the corrupted obj was there and be treated as a success sync.

root@host:~# radosgw-admin --cluster slc_ceph_ump bucket sync status --bucket=ms-nsn-prod-48
realm 2305f95c-9ec9-429b-a455-77265585ef68 (metrics)
zonegroup 9dad103a-3c3c-4f3b-87a0-a15e17b40dae (ebay)
zone 6205e53d-6ce4-4e25-a175-9420d6257345 (slc)
bucket ms-nsn-prod-48[017a0848-cf64-4879-b37d-251f72ff9750.432063.48]

source zone 017a0848-cf64-4879-b37d-251f72ff9750 (lvs)
                full sync: 0/16 shards
                incremental sync: 16/16 shards
                bucket is caught up with source