MySQL FAQs

How to create and configure an environment (host) key pair?

The environment’s (host’s) key pair enables Delphix Continuous Data Engine to SSH into the host and manage various discovery, linking, and provisioning operations. This authentication mechanism is called Username and Public Key during the environment configuration process. It is an alternative to Username/Password or Password Vault authentication.

Perform the following steps to create and configure an environment key pair during the (a) creation of an Environment or (b) addition of a new Environment User:

1. Under Login Type, select Username and Public Key.

2. Update the Username if desired.

3. The Public Key will either be presented below or select the View Public Key button.

   1. The key pair is automatically generated by the Delphix Continuous Data Engine with the Private Key pair saved locally.

4. Copy the full Public Key string that is displayed, and append it to the end of your environment’s (host’s) ~/.ssh/authorized_keys file. If this file does not exist on the host, then you must create it. 

   1. Run chmod 600 ~/.ssh/authorized_keys to allow only the file's owner to read and write to it (make sure the file is owned by you).

   2. Run chmod 755 ~ to restrict access to your home directory so that no other may write to it.

   3. Run chmod 700 ~/.ssh so that others cannot write to it. The ~/.ssh directory is not writable by group or others. Otherwise, authentication will fail.

5. Once added, select the Validate button to ensure it has been configured correctly. A success or error message will appear to direct further actions.

6. To complete the configuration, finish your creation of the Environment or select the Add button.

Why is the BLOB limited to 1GB in size?

LONGBLOBs can address up to 4 GB of memory using 32-bit binaries. However, this value is ignored as MySQL is instead bounded by the BLOB’s smaller 1 GB limit. This is a limitation introduced by the MySQL protocol. Additional information can be found in the MySQL max_allowed_packet documentation.

This question arises when the mysqldump command fails if there is more than 1 GB of data in a single LONGBLOB column or field. To resolve this issue, shrink or remove column and field data from your MySQL database that exceeds a size of 1 GB.