This post has been republished via RSS; it originally appeared at: Azure Database Support Blog articles.
Introduction:
Efficiently managing temporary failures and timeouts is crucial in production environments when connecting to databases. In this article, we’ll explore how to implement a retry mechanism with sqlcmd
in a Bash script, dynamically increasing timeouts with each failed attempt.
Problem Statement:
Operations can fail due to network issues, overloaded servers, or other temporary problems when interacting with databases. Implementing a retry mechanism helps address these temporary issues without manual intervention.
Solution Overview:
Below is a Bash script utilizing sqlcmd
to interact with an SQL Server database. The script attempts to execute an SQL command and, upon failure, retries the operation up to a maximum number of times, incrementing timeouts with each attempt.
Script Explanation:
-
Variable Declaration: The script begins by declaring variables like the maximum number of retries, counter, server, database, user, password, input file, and timeouts.
-
Main Loop: A
while
loop serves as the main retry mechanism. The script runssqlcmd
and captures its return value. -
Return Value Check: If
sqlcmd
executes successfully (return value 0), the script prints a success message and terminates. Otherwise, it prints an error message, increments timeouts and the retry counter, and sleeps for a while before retrying. -
Timeout Increment: On each failed retry, login and query timeouts are increased by 15 and 30 seconds respectively, providing more time for subsequent operations.
Conclusion:
This Bash script is a valuable tool for managing database operations that might face temporary issues. With a retry mechanism and dynamically adjusted timeouts, you can enhance the robustness and reliability of your database interactions in unstable or high-load environments. We hope this article provided insightful information on effectively implementing a retry mechanism with sqlcmd
in Bash. For optimal results, adjust variable values and timeouts to cater to your specific needs and production environment.