pt-table-checksum stuck on "Waiting to check replicas for differences"

Polyglot Projects Percona Toolkit
3

Thanks… I will.

In the slave, I saw the loop,

and I checked the log on slave, it also loop,
171129 8:34:10 88 Query SELECT MAX(chunk) FROM percona.checksums WHERE db=‘test’ AND tbl=‘_logs’ AND master_crc IS NOT NULL

171129 8:34:11 88 Query SELECT MAX(chunk) FROM percona.checksums WHERE db=‘test’ AND tbl=‘_logs’ AND master_crc IS NOT NULL

171129 8:34:12 88 Query SELECT MAX(chunk) FROM percona.checksums WHERE db=‘test’ AND tbl=‘_logs’ AND master_crc IS NOT NULL

171129 8:34:13 88 Query SELECT MAX(chunk) FROM percona.checksums WHERE db=‘test’ AND tbl=‘_logs’ AND master_crc IS NOT NULL

171129 8:34:15 88 Query SELECT MAX(chunk) FROM percona.checksums WHERE db=‘test’ AND tbl=‘_logs’ AND master_crc IS NOT NULL

171129 8:34:16 88 Query SELECT MAX(chunk) FROM percona.checksums WHERE db=‘test’ AND tbl=‘_logs’ AND master_crc IS NOT NULL

…

and the table percona.checksums has nothing.