pt-table-checksum help needed

[amir ali]

Hello,

I am newbie to percona toolkit. I want to learn about pt-table-checksum.
AFAIK, pt-table-checksum checksums table data on master and replicates checksum table on slaves to checksum data on slaves.
and compares the replicated checksum (master) and slave checksum and notify any deficiencies on console between master/slave.
But how it deals with replication stream. e.g. when checksum done on master table1 row count is 1000 rows and when it started checksum
on slave table1 row count reaches to 1500 rows now how tool will deal with this.

Secondly, i am using mix of MyISAM/INNoDB and my database size is more than 100GB and i have some of slaves replicates entire database
and some of the slaves using filtered replication. How tool will incorporates with it.

Finally, how much impact checksum will push on online queries on servers (master/slaves). Also when i ran pt-table-checksum command on master
it errors "failed to connect to slave". I am using latest version downloaded from percona site.

[amir ali]

Can someone please help.