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doc/en_US/performances.markdown

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+Kanboard Performances
+=====================
+
+According to your configuration, some features can slow down the usage of Kanboard.
+By default, all operations are synchronous and performed in the same thread as the HTTP request.
+This is a PHP limitation.
+However, it's possible to improve that.
+
+Depending on the plugins you install, communicating to external services can take hundred of milliseconds or even seconds.
+To avoid blocking the main thread, it's possible to delegate these operations to a pool of [background workers](worker.markdown).
+This setup require that you install additional software in your infrastructure.
+
+How to detect the bottleneck?
+-----------------------------
+
+- Enable the debug mode
+- Monitor the log file
+- Do something in Kanboard (drag and drop a task for example)
+- All operations are logged with the execution time (HTTP requests, Email notifications, SQL requests)
+
+Improve Email notifications speed
+---------------------------------
+
+Using the SMTP method with an external server can be very slow.
+
+Possible solutions:
+
+- Use the background workers if you still want to use SMTP
+- Use a local email relay with Postfix and use the "mail" transport
+- Use an email provider that use an HTTP API to send emails (Sendgrid, Mailgun or Postmark)
+
+Improve Sqlite performances
+---------------------------
+
+Possible solutions:
+
+- Do not use Sqlite when you have a lot of concurrency (several users), choose Postgres or Mysql instead
+- Do not use Sqlite on a shared NFS mount
+- Do not use Sqlite on a disk with poor IOPS, it's always preferable to use local SSD drives