Converting live MyISAM table to InnoDB
Assuming you don't have any triggers on that table, the simplest way to do this without locking the table is to use pt-online-schema-change.

Make sure you have enough extra disk space to accommodate this change. The table will be larger when you convert it to InnoDB, and you need to maintain both copies of the table during the conversion. For example, if your table is 100 GB make sure you have at least 200+ GB of free disk space.

You should test this out in a non-production environment first to make sure it works for you and to find out exactly how much disk space you need.

The syntax for your case is quite simple.

First do a dry run to verify that it will work:

pt-online-schema-change --alter "ENGINE=InnoDB" D=mydb,t=tracking --dry-run


Then execute it:

pt-online-schema-change --alter "ENGINE=InnoDB" D=mydb,t=tracking --execute