Using logs

Using logs

Frequently asked questions

Troubleshooting slow queries

Slow queries in MySQL are frequently the root cause of slowness in Drupal applications. Most often, slow queries are generated either by complex Views or custom code that require MySQL to process a large volume of data.

While it’s not ideal to have slow queries on your application, they are not uncommon on many large or complex applications. When they are infrequent or less severe, they will likely go unnoticed for a long period of time. However, if they become more frequent, or get slower over time, they may reach a point where they begin to stack up on each other, causing sudden performance issues and potentially taking the application offline for brief periods of time.

You can see trends in slow queries on the Stack Metrics page. This can be useful for monitoring trends over time, but you will need to take additional steps to analyze this data further by downloading and analyzing the slow query log. For more information, refer to Downloading a slow query log and Tools for parsing a slow query log.

Avoiding 404 errors

While 404 errors are not uncommon in an application’s logs, if left unaddressed, they can have a severe impact on performance over time. In many cases, you can take steps to avoid this issue. For more information, see Avoiding 404 error messages in your logs.

Troubleshooting slow queries

Slow queries in MySQL are frequently the root cause of slowness in Drupal applications. Most often, slow queries are generated either by complex Views or custom code that require MySQL to process a large volume of data.

While it’s not ideal to have slow queries on your application, they are not uncommon on many large or complex applications. When they are infrequent or less severe, they will likely go unnoticed for a long period of time. However, if they become more frequent, or get slower over time, they may reach a point where they begin to stack up on each other, causing sudden performance issues and potentially taking the application offline for brief periods of time.

You can see trends in slow queries on the Stack Metrics page. This can be useful for monitoring trends over time, but you will need to take additional steps to analyze this data further by downloading and analyzing the slow query log. For more information, refer to Downloading a slow query log and Tools for parsing a slow query log.

Avoiding 404 errors

While 404 errors are not uncommon in an application’s logs, if left unaddressed, they can have a severe impact on performance over time. In many cases, you can take steps to avoid this issue. For more information, see Avoiding 404 error messages in your logs.

Frequently asked questions