Can't get keys for table poll (Lost connection to MySQL server during query)

I am getting an error when I try to use mysqldump on a database. /usr/local/mysql/bin/mysqldump: Can't get keys for table poll (Lost connection to MySQL server during query) When this happens, I get a message in the mysql error log saying the database has been restarted. mysqld restarted on

Can't get keys for table

I am getting an error when I try to use mysqldump on a database. /usr/local/mysql/bin/mysqldump: Can't get keys for table agora (Lost connection to MySQL server during query) When this happens, I get a message in the mysql error log saying the database has been restarted. mysqld restarted on