The Stats VBucket-Seqno command is used to obtain the current High Sequence Number/VBucket UUID for one or all VBuckets on a Couchbase node.
See the stats command for details on the packet format for stats commands. Stats VBucket-Seqno can be used by placing the string vbucket-seqno into the key section of a stats packet to receive High Sequence Number/VBucket UUID pairs for all VBuckets on a given node. To receive a the High Sequence NUmber/VBucket UUID pair for a single VBucket then you can set the key in the stats command to vbucket-seqno <vbid>.
The stats response from a Stats VBucket-Seqno command will look as follows:
vb_0:high_seqno 45
vb_0:vb_uuid 2723958720985
vb_1:high_seqno 78
vb_1:vb_uuid 7851085629020
vb_2:high_seqno 56
vb_2:vb_uuid 4560392056902
...
PROTOCOL_BINARY_RESPONSE_EINVAL (0x04)
If data in this packet is malformed or incomplete then this error is returned.
PROTOCOL_BINARY_RESPONSE_NOT_MY_VBUCKET (0x07)
If you specified a specific VBucket and that VBucket does not exist.
This command is typically used before creating an UPR stream in order to find out what the sequence number is of the last mutation the server has for a given VBucket at the time the Stats VBucket-Seqno command was received.