Maintenance Tasks

Additional commands are provided for common maintenance tasks like upgrading the application, migrating the database and pruning expired resumption tokens.

Maintenance Mode

When performing maintenance tasks like upgrading the application or importing large sets of records it is advisable to put the application into maintenance mode to prevent users from receiving inconsistent data.

# Show current maintenance mode status
bin/cli app:maintenance:mode

# Enable maintenance mode
bin/cli app:maintenance:mode on

# Disable maintenance mode
bin/cli app:maintenance:mode off

While maintenance mode is enabled all requests to the OAI-PMH2 Data Provider will return HTTP status code 503 (Service Unavailable) along with a Retry-After header indicating it will be available again after approximately 5 minutes.

Pruning Expired Tokens

When serving large amounts of records the OAI-PMH2 Data Provider splits the result set in batches issuing resumption tokens for flow control. Those are kept in the database, but expire after a certain time. It is therefore advisable to regularly remove expired tokens.

# Delete expired tokens
bin/cli oai:prune:tokens

Instead of running this command manually over and over again it is recommended to set up a maintenance cronjob.

Performing Upgrades

Upgrading the OAI-PMH2 Data Provider is as easy as running a single command.

# Upgrade to the latest stable release
bin/cli app:upgrade

For more information and step-by-step instructions visit the documentation on upgrading.

Initializing a new database or migrating an existing database after a manual upgrade can be performed by running the following command. (app:install:db and app:upgrade:db are aliases of the same command.)

# Migrate (or initialize) the database
bin/cli app:upgrade:db

Be aware that migrations can potentially lead to data loss. Always keep a backup when performing upgrades and migrations!