@recaptime-dev's working patches + fork for Phorge, a community fork of Phabricator. (Upstream dev and stable branches are at upstream/main and upstream/stable respectively.)
hq.recaptime.dev/wiki/Phorge
phorge
phabricator
Provide an ad-hoc maintenance lock for clustered repositories
Summary: Ref T13614. Provide "bin/repository lock" to temporarily lock repositories for manual maintenance.
Test Plan:
- Read instructions.
- Used `bin/repository lock` according to the instructions.
- Saw Storage tab in Diffusion report lock held during maintenance, released after it completes.
- Saw "maintenance" push log generated and repository version bump.
- Tried to lock some invalid repositories.
Maniphest Tasks: T13614
Differential Revision: https://secure.phabricator.com/D21671
+222
+2
src/__phutil_library_map__.php
+2
src/__phutil_library_map__.php
···
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'PhabricatorRepositoryManagementImportingWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementImportingWorkflow.php',
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'PhabricatorRepositoryManagementListPathsWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementListPathsWorkflow.php',
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'PhabricatorRepositoryManagementListWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementListWorkflow.php',
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'PhabricatorRepositoryManagementLockWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementLockWorkflow.php',
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'PhabricatorRepositoryManagementMaintenanceWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementMaintenanceWorkflow.php',
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'PhabricatorRepositoryManagementMarkImportedWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementMarkImportedWorkflow.php',
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'PhabricatorRepositoryManagementMarkReachableWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementMarkReachableWorkflow.php',
···
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'PhabricatorRepositoryManagementImportingWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
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'PhabricatorRepositoryManagementListPathsWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
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'PhabricatorRepositoryManagementListWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
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'PhabricatorRepositoryManagementLockWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
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'PhabricatorRepositoryManagementMaintenanceWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
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'PhabricatorRepositoryManagementMarkImportedWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
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'PhabricatorRepositoryManagementMarkReachableWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
+139
src/applications/repository/management/PhabricatorRepositoryManagementLockWorkflow.php
+139
src/applications/repository/management/PhabricatorRepositoryManagementLockWorkflow.php
···
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<?php
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final class PhabricatorRepositoryManagementLockWorkflow
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extends PhabricatorRepositoryManagementWorkflow {
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protected function didConstruct() {
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$this
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->setName('lock')
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->setExamples('**lock** [options] __repository__ ...')
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->setSynopsis(
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pht(
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'Temporarily lock clustered repositories to perform maintenance.'))
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->setArguments(
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array(
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array(
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'name' => 'repositories',
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'wildcard' => true,
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),
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));
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}
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public function execute(PhutilArgumentParser $args) {
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$viewer = $this->getViewer();
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$repositories = $this->loadRepositories($args, 'repositories');
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if (!$repositories) {
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throw new PhutilArgumentUsageException(
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pht('Specify one or more repositories to lock.'));
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}
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foreach ($repositories as $repository) {
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$display_name = $repository->getDisplayName();
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if (!$repository->isHosted()) {
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throw new PhutilArgumentUsageException(
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pht(
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'Unable to lock repository "%s": only hosted repositories may be '.
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'locked.',
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$display_name));
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}
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if (!$repository->supportsSynchronization()) {
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throw new PhutilArgumentUsageException(
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pht(
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'Unable to lock repository "%s": only repositories that support '.
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'clustering may be locked.',
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$display_name));
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}
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if (!$repository->getAlmanacServicePHID()) {
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throw new PhutilArgumentUsageException(
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pht(
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'Unable to lock repository "%s": only clustered repositories '.
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'may be locked.',
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$display_name));
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}
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}
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$diffusion_phid = id(new PhabricatorDiffusionApplication())
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->getPHID();
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$locks = array();
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foreach ($repositories as $repository) {
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$engine = id(new DiffusionRepositoryClusterEngine())
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->setViewer($viewer)
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->setActingAsPHID($diffusion_phid)
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->setRepository($repository);
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$event = $engine->newMaintenanceEvent();
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$logs = array();
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$logs[] = $engine->newMaintenanceLog();
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$locks[] = array(
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'repository' => $repository,
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'engine' => $engine,
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'event' => $event,
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'logs' => $logs,
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);
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}
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$display_list = new PhutilConsoleList();
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foreach ($repositories as $repository) {
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$display_list->addItem(
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pht(
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'%s %s',
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$repository->getMonogram(),
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$repository->getName()));
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}
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echo tsprintf(
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"%s\n\n%B\n",
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pht('These repositories will be locked:'),
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$display_list->drawConsoleString());
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echo tsprintf(
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"%s\n",
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pht(
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'While the lock is held: users will be unable to write to this '.
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'repository, and you may safely perform working copy maintenance '.
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'on this node in another terminal window.'));
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$query = pht('Lock repositories and begin maintenance?');
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if (!phutil_console_confirm($query)) {
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throw new ArcanistUserAbortException();
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}
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foreach ($locks as $key => $lock) {
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$engine = $lock['engine'];
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$engine->synchronizeWorkingCopyBeforeWrite();
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}
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echo tsprintf(
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"%s\n",
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pht(
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'Repositories are now locked. You may begin maintenance in '.
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'another terminal window. Keep this process running until '.
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'you complete the maintenance, then confirm that you are ready to '.
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'release the locks.'));
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while (!phutil_console_confirm('Ready to release the locks?')) {
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// Wait for the user to confirm that they're ready.
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}
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foreach ($locks as $key => $lock) {
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$lock['event']->saveWithLogs($lock['logs']);
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$engine = $lock['engine'];
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$engine->synchronizeWorkingCopyAfterWrite();
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}
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echo tsprintf(
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"%s\n",
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pht('Done.'));
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return 0;
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}
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}
+81
src/docs/user/cluster/cluster_repositories.diviner
+81
src/docs/user/cluster/cluster_repositories.diviner
···
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data more easily in a wider range of disaster situations.
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Ad-Hoc Maintenance Locks
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========================
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Occasionally, you may want to perform maintenance to a clustered repository
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which requires you modify the actual content of the repository.
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For example: you might want to delete a large number of old or temporary
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branches; or you might want to merge a very large number of commits from
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another source.
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These operations may be prohibitively slow or complex to perform using normal
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pushes. In cases where you would prefer to directly modify a working copy, you
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can use a maintenance lock to safely make a working copy mutable.
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If you simply perform this kind of content-modifying maintenance by directly
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modifying the repository on disk with commands like `git update-ref`, your
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changes may either encounter conflicts or encounter problems with change
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propagation.
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You can encounter conflicts because directly modifying the working copy on disk
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won't prevent users or Phabricator itself from performing writes to the same
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working copy at the same time. Phabricator does not compromise the lower-level
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locks provided by the VCS so this is theoretically safe -- and this rarely
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causes any significant problems in practice -- but doesn't make things any
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simpler or easier.
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Your changes may fail to propagate because writing directly to the repository
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doesn't turn it into the new cluster leader after your writes complete. If
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another node accepts the next push, it will become the new leader -- without
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your changes -- and all other nodes will synchronize from it.
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Note that some maintenance operations (like `git gc`, `git prune`, or
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`git repack`) do not modify repository content. In theory, these operations do
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not require a maintenance lock: lower-level Git locks should protect
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them from conflicts, and they can not be affected by propagation issues because
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they do not propagate. In practice, these operations are not conflict-free in
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all circumstances. Using a maintenance lock may be overkill, but it's probably
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still a good idea.
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To use a maintenance lock:
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- Open two terminal windows. You'll use one window to hold the lock and a
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second window to perform maintenance.
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- Run `bin/repository lock <repository> ...` in one terminal.
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- When the process reports that repositories are locked, switch to the second
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terminal and perform maintenance. The `repository lock` process should
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still be running in your first terminal.
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- After maintenance completes, switch back to the first terminal and answer
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the prompt to confirm maintenance is complete.
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The workflow looks something like this:
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```
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$ ./bin/repository lock R2
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These repositories will be locked:
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- R2 Git Test Repository
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While the lock is held: users will be unable to write to this repository,
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and you may safely perform working copy maintenance on this node in another
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terminal window.
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Lock repositories and begin maintenance? [y/N] y
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Repositories are now locked. You may begin maintenance in another terminal
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window. Keep this process running until you complete the maintenance, then
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confirm that you are ready to release the locks.
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Ready to release the locks? [y/N] y
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Done.
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```
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As maintenance completes, the push log for the repository will be updated to
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reflect that you performed maintenance.
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If the lock is interrupted, you may encounter a "Write Interruptions" condition
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described earlier in this document. See that section for details. In most
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cases, you can resolve this issue by demoting the node you are working on.
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Next Steps
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==========
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