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@@ -114,12 +114,17 @@ class Multi
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multi.exec releaseLock
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class MigrationClient
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- constructor: (old_settings, new_settings) ->
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- @rclient_old = redis.createClient(old_settings)
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- @rclient_new = redis.createClient(new_settings)
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+ constructor: (@old_settings, @new_settings) ->
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+ @rclient_old = redis.createClient(@old_settings)
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+ @rclient_new = redis.createClient(@new_settings)
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@new_key_schema = new_settings.key_schema
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- @migration_phase = new_settings.migration_phase
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+ # check that migration phase is valid on startup
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+ @getMigrationPhase()
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+
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+ getMigrationPhase: () ->
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+ @migration_phase = @new_settings.migration_phase # FIXME: allow setting migration phase while running for testing
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throw new Error("invalid migration phase") unless @migration_phase in ['prepare', 'switch', 'rollback']
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+ return @migration_phase
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getMigrationStatus: (key, migrationKey, callback) ->
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async.series [
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@@ -136,12 +141,12 @@ class MigrationClient
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findQueue: (key, callback) ->
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project_id = getProjectId(key)
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migrationKey = @new_key_schema.projectHistoryMigrationKey({project_id})
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-
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+ migration_phase = @getMigrationPhase() # allow setting migration phase while running for testing
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@getMigrationStatus key, migrationKey, (err, migrationKeyExists, newQueueExists, oldQueueExists) =>
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return callback(err) if err?
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# In all cases, if the migration key exists we must always write to the
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# new redis, unless we are rolling back.
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- if @migration_phase is "prepare"
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+ if migration_phase is "prepare"
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# in this phase we prepare for the switch, when some docupdaters will
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# start setting the migration flag. We monitor the migration key and
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# write to the new redis if the key is present, but we do not set the
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@@ -154,7 +159,7 @@ class MigrationClient
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else
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logger.debug {project_id}, "using old client because migration key does not exist"
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return callback(null, @rclient_old)
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- else if @migration_phase is "switch"
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+ else if migration_phase is "switch"
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# As we deploy the "switch" phase new docupdaters will set the migration
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# flag for projects which have an empty queue in the old redis, and
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# write updates into the new redis. Existing docupdaters still in the
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@@ -175,7 +180,7 @@ class MigrationClient
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return callback(err) if err?
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logger.debug {key: key}, "switching to new redis because old queue is empty"
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return callback(null, @rclient_new)
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- else if @migration_phase is "rollback"
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+ else if migration_phase is "rollback"
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# If we need to roll back gracefully we do the opposite of the "switch"
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# phase. We use the new redis when the migration key is set and the
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# queue exists in the new redis, but if the queue in the new redis is
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@@ -194,7 +199,7 @@ class MigrationClient
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logger.debug {project_id}, "using old client because migration key does not exist"
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return callback(null, @rclient_old)
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else
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- logger.error {key: key, migration_phase: @migration_phase}, "unknown migration phase"
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+ logger.error {key: key, migration_phase: migration_phase}, "unknown migration phase"
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callback(new Error('invalid migration phase'))
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multi: () ->
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new Multi(@)
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Brian Gough