PowerShell Scripting to Replicate Redis Data to MySQL

The CData Cmdlets for Redis offer live access to Redis data from within PowerShell. Using PowerShell scripts, you can easily automate regular tasks like data replication. This article will walk through using the CData Cmdlets for Redis and the CData Cmdlets for MySQL in PowerShell to replicate Redis data to a MySQL database.

After obtaining the needed connection properties, accessing Redis data in PowerShell and preparing for replication consists of four basic steps.

Set the following connection properties to connect to a Redis instance:

• Server: Set this to the name or address of the server your Redis instance is running on. You can specify the port in Port.
• Password: Set this to the password used to authenticate with a password-protected Redis instance , using the Redis AUTH command.

Set UseSSL to negotiate SSL/TLS encryption when you connect.

Collecting Redis Data

1. Install the module:

   Install-Module RedisCmdlets

2. Connect to Redis:

   $redis = Connect-Redis -Server $Server -Port $Port -Password $Password

3. Retrieve the data from a specific resource:

   $data = Select-Redis -Connection $redis -Table "Customers"

   You can also use the Invoke-Redis cmdlet to execute pure SQL-92 statements:

   $data = Invoke-Redis -Connection $redis -Query 'SELECT * FROM Customers WHERE Country = @Country' -Params @{'@Country'='US'}

4. Save a list of the column names from the returned data.

   $columns = ($data | Get-Member -MemberType NoteProperty | Select-Object -Property Name).Name

Inserting Redis Data into the MySQL Database

With the data and column names collected, you are ready to replicate the data into a MySQL database.

1. Install the module:

   Install-Module MySQLCmdlets

2. Connect to MySQL, using the server address and port of the MySQL server, valid user credentials, and a specific database with the table in which the data will be replicated:

   $mysql = Connect-MySQL -User $User -Password $Password -Database $Database -Server $Server -Port $Port

3. Loop through the Redis data, store the values, and use the Add-MySQL cmdlet to insert the data into the MySQL database, one row at a time. In this example, the table will need to have the same name as the Redis resource (Customers) and to exist in the database.

   $data | % { $row = $_ $values = @() $columns | % { $col = $_ $values += $row.$($col) } Add-MySQL -Connection $mysql -Table "Customers" -Columns $columns -Values $values }

You have now replicated your Redis data to a MySQL database. This gives you freedom to work with Redis data in the same way that you work with other MySQL tables, whether that is performing analytics, building reports, or other business functions.

Notes

• Once you have connected to Redis and MySQL in PowerShell, you can pipe command results to perform the replication in a single line:

  Select-Redis -Connection $redis -Table "Customers" | % { $row = $_ $values = @() $columns | % { $col = $_ $values += $row.$($col) } Add-MySQL -Connection $mysql -Table "Customers" -Columns $columns -Values $values }

• If you wish to replicate the Redis data to another database using another PowerShell module, you will want to exclude the Columns, Connection, and Table columns from the data returned by the Select-Redis cmdlet since those columns are used to help pipe data from one CData cmdlet to another:

  $columns = ($data | Get-Member -MemberType NoteProperty | Select-Object -Property Name).Name | ? {$_ -NotIn @('Columns','Connection','Table')}