service/history/execution/mutable_state_builder.go (15 lines):
	- line 126: // TODO: remove this struct after all 2DC workflows complete
	- line 144: // TODO: persist this to db
	- line 344: // TODO: remove this after all 2DC workflows complete
	- line 582: // TODO: remove this after all 2DC workflows complete
	- line 613: // TODO: remove this after all 2DC workflows complete
	- line 1122: // TODO: decide if we can add execution time in execution info.
	- line 2035: // TODO: we will release the restriction when reset API allow those pending
	- line 2876: // TODO: Evaluate if we need cancelRequestID also part of history event
	- line 2993: // TODO: Consider also writing signalRequestID to history event
	- line 3171: // TODO: Time skew need to be taken in to account.
	- line 3965: // TODO mutable state should generate corresponding transfer / timer tasks according to
	- line 3968: // TODO convert AddTransferTasks to prepareTransferTasks
	- line 3982: // TODO convert AddTimerTasks to prepareTimerTasks
	- line 4153: // TODO do we need the functionality to generate snapshot with buffered events?
	- line 4697: // TODO: This will be removed once our reset allows childWFs


service/history/task/transfer_active_task_executor.go (9 lines):
	- line 267: // TODO: for normal decision, we don't know if there's a scheduleToStart
	- line 347: // TODO: this helper function performs three operations:
	- line 609: // TODO: handle the case where target domain does not exist
	- line 716: // TODO: here we should also RemoveSignalMutableState from target workflow
	- line 728: // TODO: handle the case where target domain does not exist
	- line 870: // TODO: handle the case where target domain does not exist
	- line 932: // TODO: we should also handle domain not exist error here
	- line 1143: // TODO: current reset doesn't allow childWFs, in the future we will release this restriction
	- line 1525: // TODO: we don't have to do this check here, as we hold the mutable state lock


common/dynamicconfig/constants.go (9 lines):
	- line 1400: // TODO: https://github.com/uber/cadence/issues/3861
	- line 1405: // TODO: https://github.com/uber/cadence/issues/3861
	- line 1762: // Only implemented for single SQL database. TODO https://github.com/uber/cadence/issues/4064 for supporting multiple/sharded SQL database and NoSQL
	- line 1923: // TODO: https://github.com/uber/cadence/issues/3861
	- line 1928: // TODO: https://github.com/uber/cadence/issues/3861
	- line 1933: // TODO: https://github.com/uber/cadence/issues/3861
	- line 1943: // TODO: https://github.com/uber/cadence/issues/3861
	- line 2181: // TODO: https://github.com/uber/cadence/issues/3861
	- line 2186: // TODO: https://github.com/uber/cadence/issues/3861


common/persistence/data_manager_interfaces.go (6 lines):
	- line 79: // TODO we can remove it after fixing all the query templates and when
	- line 338: ExpirationSeconds int32 // TODO: is this field useful?
	- line 348: // TODO: remove this struct after all 2DC workflows complete
	- line 490: ReplicationState    *ReplicationState // TODO: remove this after all 2DC workflows complete
	- line 1087: // TODO: replace this with an iterator that can configure min and max index.
	- line 1759: // TODO: do we really need to deep copy those fields?


common/config/config.go (6 lines):
	- line 180: // TODO This config doesn't belong here, needs refactoring
	- line 184: // TODO: move dynamic config out of static config
	- line 187: // TODO: move dynamic config out of static config
	- line 349: // TODO can we remove it?
	- line 358: // TODO can we remove it?
	- line 661: // TODO: remove this at the point when we decided to make some breaking changes in config.


common/persistence/serialization/interfaces.go (5 lines):
	- line 65: Name                        string // TODO: This field seems not to be required. We already store domain name in another column.
	- line 86: FailoverEndTimestamp        *time.Time // TODO: There is logic checking if it's nil, should revisit this
	- line 115: CompletionEventBatchID             *int64 // TODO: This is not updated because of backward compatibility issue. Should revisit it later.
	- line 127: LastWriteEventID                   *int64 // TODO: We have logic checking if LastWriteEventID != nil. The field seems to be deprecated. Should revisit it later.
	- line 302: TimeoutType     *int16 // TODO: The default value for TimeoutType doesn't make sense. No equivalent value for nil.


service/history/execution/context.go (5 lines):
	- line 66: // TODO: refactor those tests
	- line 729: // TODO remove updateCondition in favor of condition in mutable state
	- line 862: // TODO remove updateCondition in favor of condition in mutable state
	- line 1189: // TODO: is timeout error retryable for create workflow?
	- line 1296: // TODO: Call the Task Validation here so that it happens whenever an error happen during Update.


service/worker/batcher/workflow.go (5 lines):
	- line 89: // TODO https://github.com/uber/cadence/issues/2159
	- line 97: // TODO https://github.com/uber/cadence/issues/2159
	- line 135: // TODO we will implement smarter way than this static rate limiter: https://github.com/uber/cadence/issues/2138
	- line 314: // TODO https://github.com/uber/cadence/issues/2154
	- line 514: // TODO https://github.com/uber/cadence/issues/2159


common/persistence/sql/sqlplugin/interfaces.go (5 lines):
	- line 196: ShardID      int // this is DBShardID, not historyShardID (TODO: maybe rename it for clarification)
	- line 225: ShardID              int // this is DBShardID, not historyShardID (TODO: maybe rename it for clarification)
	- line 244: ShardID      int // this is DBShardID, not historyShardID (TODO: maybe rename it for clarification)
	- line 262: ShardID             int // this is DBShardID, not historyShardID (TODO: maybe rename it for clarification)
	- line 674: // TODO: add cross-cluster tasks methods


service/history/engine/engineimpl/historyEngine.go (4 lines):
	- line 1669: // TODO: we need to consider adding execution time to mutable state
	- line 1719: // TODO: move to mutable state instead of loading it from event
	- line 3055: // TODO: consider defining a new interface in persistence package
	- line 3536: // TODO when https://github.com/uber/cadence/issues/2420 is finished, remove this block,


service/matching/matchingEngine.go (4 lines):
	- line 58: // TODO: Switch implementation from lock/channel based to a partitioned agent
	- line 451: // TODO: Is empty poll the best reply for errPumpClosed?
	- line 467: // TODO: Maybe add history expose here?
	- line 578: // TODO: Is empty poll the best reply for errPumpClosed?


service/history/task/task.go (4 lines):
	- line 85: // TODO: following three fields should be removed after new task lifecycle is implemented
	- line 187: // TODO: after mergering active and standby queue,
	- line 300: // TODO remove this error check special case
	- line 413: // TODO: for now only resubmit active task on Nack()


common/persistence/sql/sql_execution_store_util.go (3 lines):
	- line 55: // TODO Remove me if UPDATE holds the lock to the end of a transaction
	- line 220: // TODO Is there a way to modify the various map tables without fear of other people adding rows after we delete, without locking the executions row?
	- line 1352: // TODO: this case seems to be always false


service/history/replication/task_processor.go (3 lines):
	- line 277: // TODO: when we support prefetching, LastRetrievedMessageID can be different than LastProcessedMessageID
	- line 300: // TODO: move to MultiStageRateLimiter
	- line 432: // TODO: uncomment this when the execution fixer workflow is ready


service/history/reset/resetter.go (3 lines):
	- line 224: // TODO right now only signals are eligible for reapply, so we can directly skip the whole reapply process
	- line 462: // TODO change this logic to fetching all workflow [baseWorkflow, currentWorkflow]
	- line 535: // TODO change this logic to fetching all workflow [baseWorkflow, currentWorkflow]


service/history/decision/task_handler.go (3 lines):
	- line 533: // TODO: serialize reason somehow, may deserve a new field / wrapped errors
	- line 611: // TODO deletion of timer fired event refreshing hasUnhandledEventsBeforeDecisions
	- line 811: Details: nil, // TODO: serialize continue-as-new data somehow, may deserve a new field


common/persistence/nosql/nosqlplugin/cassandra/visibility.go (3 lines):
	- line 41: // TODO: Cassandra implementation ignores search attributes
	- line 88: // TODO implement it when where is a need
	- line 514: // TODO: may return badRequestError


service/frontend/api/handler.go (3 lines):
	- line 147: // TODO: Get warmup duration from config. Even better, run proactive checks such as probing downstream connections.
	- line 366: // TODO: call remote clusters to verify domain data
	- line 2082: // TODO: for now we only log the invalid timeout (this is done inside the helper function) in case


service/history/execution/cache.go (3 lines):
	- line 136: // TODO This will create a closure on every request.
	- line 234: // TODO This will create a closure on every request.
	- line 297: // TODO see issue #668, there are certain type or errors which can bypass the clear


common/reconciliation/invariant/staleWorkflow.go (3 lines):
	- line 163: // TODO: ^ similar check for current record?  Bad-current can sometimes block a different concrete.
	- line 197: // TODO: handle current deletion?
	- line 258: // TODO: what exactly is zombie?  seems like probably "current but no concrete" but I'm surprised this is in the state.


common/persistence/nosql/nosql_execution_store_util.go (3 lines):
	- line 597: // TODO: remove this logic once all workflows before 0.26.x are completed
	- line 604: // TODO also need to set the start / current / last write version
	- line 635: // TODO: remove this logic once all workflows before 0.26.x are completed


common/persistence/sql/sql_history_store.go (3 lines):
	- line 170: // TODO the inner pagination token can be replaced by a dummy token
	- line 461: // TODO: Limit the underlying query to a specific shard at a time. See https://github.com/uber/cadence/issues/4064
	- line 516: // TODO: this is broken for multi-sharding: the shardID should increase if there are less rows than request pageSize,


host/service.go (2 lines):
	- line 50: // TODO: Service contains many methods that are not used now that we have resource bean, these should be cleaned up
	- line 102: // TODO: have a better name for Service.


common/persistence/nosql/nosqlplugin/interfaces.go (2 lines):
	- line 253: // TODO deprecated this in the future in favor of SelectVisibility
	- line 273: // TODO separate in the future when need it


tools/cli/admin.go (2 lines):
	- line 477: // TODO: do we still need this command given that kafka replication has been deprecated?
	- line 517: // TODO: move this command be a subcommand of admin workflow


service/history/execution/mutable_state_task_generator.go (2 lines):
	- line 310: // TODO EventID seems not used at all
	- line 433: // TODO remove this block after Mar, 1th, 2020


common/config/cluster.go (2 lines):
	- line 155: // TODO: remove this after 0.23 and mention a breaking change in config.
	- line 161: // TODO: remove this after 0.23 and mention a breaking change in config.


service/history/task/timer_task_executor_base.go (2 lines):
	- line 118: // TODO: @ycyang once archival backfill is in place cluster:paused && domain:enabled should be a nop rather than a delete
	- line 307: // TODO: expose GetVisibilityManager method on shardContext interface


common/metrics/defs.go (2 lines):
	- line 809: // TODO: move them to internal repo once cadence plugin model is in place.
	- line 2126: // TODO: move them to internal repo once cadence plugin model is in place.


common/persistence/historyManager.go (2 lines):
	- line 425: // TODO: consider if it's possible to remove this branch
	- line 505: // TODO: in this case, some events returned can be invalid(stale). application layer need to make sure it won't make any problems to XDC


service/history/queue/interface.go (2 lines):
	- line 64: // TODO: add Offload() method
	- line 85: // TODO: add Offload() method


common/persistence/nosql/nosqlplugin/cassandra/admin.go (2 lines):
	- line 73: // TODO: should we remove the second condition?
	- line 84: // TODO: should we remove the second condition?


tools/cli/domain_utils.go (2 lines):
	- line 72: // TODO when https://github.com/urfave/cli/pull/392 & v2 is released
	- line 128: // TODO when https://github.com/urfave/cli/pull/392 & v2 is released


service/history/decision/handler.go (2 lines):
	- line 56: // TODO also include the handle of decision timeout here
	- line 516: // TODO: replace the poll request


canary/batch.go (2 lines):
	- line 44: // TODO: to get rid of them:
	- line 56: // TODO: to get rid of it:


service/history/queue/processing_queue.go (2 lines):
	- line 45: metricsClient metrics.Client // TODO: emit metrics
	- line 187: // TODO: this means the task has been submitted before, we should mark the task state accordingly and


proto/persistenceblobs/v1/message.proto (2 lines):
	- line 1033: // TODO: deprecate once NDC migration is done.
	- line 1037: // TODO: deprecate once kafka deprecation is done.


service/history/queue/processor_base.go (2 lines):
	- line 44: updateClusterAckLevelFn       func(task.Key) error // TODO: deprecate this in favor of updateProcessingQueueStatesFn
	- line 161: // TODO: consider move pendingTasksTime metrics from shardInfoScope to queue processor scope


common/types/mapper/proto/api.go (1 line):
	- line 4453: InitiatedId:       common.Int64Default(initiatedID), // TODO: we need to figure out whetherrr this field is needed or not


common/persistence/versionHistory.go (1 line):
	- line 477: // TODO maybe we need more strict validation


common/persistence/nosql/nosqlplugin/mongodb/plugin.go (1 line):
	- line 62: // TODO CreateDB/CreateAdminDB don't pass in context.Context so we are using background for now


common/persistence/data_store_interfaces.go (1 line):
	- line 345: ReplicationState *ReplicationState // TODO: remove this after all 2DC workflows complete


common/persistence/operationModeValidator.go (1 line):
	- line 212: // TODO remove case 1 & 2 support once 2DC is deprecated


common/collection/pagingIterator.go (1 line):
	- line 38: // TODO: this implementation should be removed in favor of pagination/iterator.go


common/persistence/jsonHistoryTokenSerializer.go (1 line):
	- line 30: // TODO remove LastEventVersion once 3+DC is enabled for all workflow


service/history/ndc/new_workflow_transaction_manager.go (1 line):
	- line 259: // TODO: add functional test for this case.


service/history/shard/controller.go (1 line):
	- line 71: // TODO: consider converting to a unified describe method


service/history/task/timer_standby_task_executor.go (1 line):
	- line 108: // TODO: add error logs


common/persistence/sql/sqlplugin/postgres/admin.go (1 line):
	- line 59: // TODO https://github.com/uber/cadence/issues/2893


common/persistence/nosql/nosqlplugin/cassandra/workflow.go (1 line):
	- line 195: // TODO: remove this after all 2DC workflows complete


common/persistence/tasks.go (1 line):
	- line 207: EventID     int64 // TODO this attribute is not used?


service/history/ndc/transaction_manager.go (1 line):
	- line 319: // TODO when https://github.com/uber/cadence/issues/2420 is finished, remove this block,


common/persistence/nosql/nosqlplugin/cassandra/domain.go (1 line):
	- line 483: // TODO ??? really????


common/persistence/nosql/nosql_execution_store.go (1 line):
	- line 214: // TODO: ?? would it change at all ??


common/persistence/sql/sql_execution_store.go (1 line):
	- line 1444: // TODO: remove this after all 2DC workflows complete


service/history/task/timer_active_task_executor.go (1 line):
	- line 643: // TODO remove this block after Mar, 1th, 2020


schema/cassandra/cadence/schema.cql (1 line):
	- line 116: -- TODO: Remove fields that are left over from activity and workflow tasks.


client/history/client.go (1 line):
	- line 1100: // TODO: consider emitting a metric for number of redirects


common/persistence/nosql/nosqlplugin/cassandra/workflow_utils.go (1 line):
	- line 977: // TODO: if possible, remove it in the future or add more comment of why we need this conversion


common/elasticsearch/interfaces.go (1 line):
	- line 108: // TODO remove it in https://github.com/uber/cadence/issues/3682


common/persistence/nosql/nosqlplugin/cassandra/workflow_cql.go (1 line):
	- line 275: // TODO: remove replication_state after all 2DC workflows complete


service/history/replication/task_fetcher.go (1 line):
	- line 40: // TODO: reuse the interface and implementation defined in history/task package


service/history/shard/context.go (1 line):
	- line 1594: // TODO remove once migrated to global event cache


common/persistence/sql/factory.go (1 line):
	- line 121: // TODO sortByCloseTime will be removed and implemented for https://github.com/uber/cadence/issues/3621


common/domain/attrValidator.go (1 line):
	- line 94: // TODO: https://github.com/uber/cadence/issues/4345 add checking for "pending active" as well


service/history/ndc/replication_task.go (1 line):
	- line 322: // TODO add validation on version history


common/constants.go (1 line):
	- line 183: // TODO: we can remove +2 from the following definition


bench/worker.go (1 line):
	- line 126: // TODO: do we need these limits?


tools/cli/workflow.go (1 line):
	- line 330: // TODO https://github.com/uber/cadence/issues/2930


service/matching/pollerHistory.go (1 line):
	- line 88: // TODO add IP, T1396795


bench/load/cancellation/workflow.go (1 line):
	- line 357: // TODO: uncomment the following check after cancellation test is rewritten.


common/persistence/sql/sqlplugin/postgres/typeconv.go (1 line):
	- line 31: // TODO https://github.com/uber/cadence/issues/2892


common/persistence/client/factory.go (1 line):
	- line 89: // TODO We temporarily using sortByCloseTime to determine whether or not ListClosedWorkflowExecutions should


common/elasticsearch/client/client.go (1 line):
	- line 47: // @TODO consider to extract Bulk Processor as a separate entity


tools/sql/clitest/connTest.go (1 line):
	- line 80: // TODO refactor the whole package to support testing against Postgres


common/persistence/sql/sqlplugin/mysql/plugin.go (1 line):
	- line 127: // TODO: create a way to set MinVersion and CipherSuites via cfg.


service/history/task/task_util.go (1 line):
	- line 376: // TODO: refactor loadMutableStateForXXXTask function implementation to avoid duplication


common/log/tag/tags.go (1 line):
	- line 911: // TODO: move them to internal repo once cadence plugin model is in place.


schema/cassandra/cadence/versioned/v0.1/base.cql (1 line):
	- line 43: -- TODO: Remove fields that are left over from activity and workflow tasks.


service/history/task/cross_cluster_source_task_executor.go (1 line):
	- line 440: // TODO: here we should also RemoveSignalMutableState from target workflow


tools/sql/conn.go (1 line):
	- line 77: // TODO pass in context timeout value from command line param


host/onebox.go (1 line):
	- line 579: // TODO: this is not correct when there are multiple history hosts as later client will overwrite previous ones.


common/persistence/nosql/nosqlplugin/cassandra/workflow_parsing_utils.go (1 line):
	- line 185: // TODO: remove this after all 2DC workflows complete


common/persistence/sql/sql_task_store.go (1 line):
	- line 550: // TODO: Limit this query to a specific shard at a time. See https://github.com/uber/cadence/issues/4064


service/history/task/cross_cluster_task.go (1 line):
	- line 736: // TODO: we should check the TargetDomainIDs field


tools/cli/workflow_commands.go (1 line):
	- line 935: // TODO: Idea here is only display decision task original scheduled timestamp if user are


service/matching/forwarder.go (1 line):
	- line 257: // TODO: consider having separate token pools for different isolation groups


host/testcluster.go (1 line):
	- line 290: // TODO refactor to support other NoSQL


common/testing/history_event_util.go (1 line):
	- line 534: // TODO: bypass activity cancel request event. Support this event later.


service/history/queue/transfer_queue_validator.go (1 line):
	- line 139: // TODO: implement an event logger for queue processor and dump all events when this validation fails.


common/elasticsearch/common.go (1 line):
	- line 31: // TODO https://github.com/uber/cadence/issues/3686


common/persistence/nosql/nosql_task_store.go (1 line):
	- line 66: // TODO: It's unclear if this's necessary or possible for NoSQL


bench/load/cron/workflow.go (1 line):
	- line 190: // TODO: it's possible that the launcher workflow is started by another cron


service/history/task/transfer_standby_task_executor.go (1 line):
	- line 112: // TODO: add error logs


schema/cassandra/cadence/versioned/s0.0-0.23/schema_0_23.cql (1 line):
	- line 99: -- TODO: Remove fields that are left over from activity and workflow tasks.


service/history/config/config.go (1 line):
	- line 256: // TODO https://github.com/uber/cadence/issues/2357


canary/canary.go (1 line):
	- line 159: // TODO: improvement: compare the cron schedule to decide whether or not terminating the current one


service/history/queue/timer_queue_processor.go (1 line):
	- line 273: // TODO: Below Add call has no effect, understand the underlying intent and fix it.


service/worker/scanner/executions/current_execution.go (1 line):
	- line 151: // TODO: yes, this DOES incorrectly use the concrete execution fixer manager, which does not work.


common/elasticsearch/bulk/backoff.go (1 line):
	- line 31: // TODO https://github.com/uber/cadence/issues/3676


service/frontend/admin/handler.go (1 line):
	- line 1370: // TODO currently, this API is only going to be used by re-send history events


service/matching/taskReader.go (1 line):
	- line 197: // TODO: Should we ever stop retrying on db errors?


service/history/workflow/util.go (1 line):
	- line 180: // TODO: deprecate and use UpdateWithActionFunc


service/history/execution/mutable_state_decision_task_manager.go (1 line):
	- line 385: // TODO: https://github.com/uber/cadence/issues/2357:


service/matching/taskListManager.go (1 line):
	- line 246: // TODO: we don't see this error in our logs, we might be able to remove this error


common/messaging/kafka/producer_impl.go (1 line):
	- line 59: // TODO implement context when https://github.com/Shopify/sarama/issues/1849 is supported


common/quotas/global/algorithm/requestweighted.go (1 line):
	- line 465: // TODO: too costly? can check the first-N% each time and it'll eventually visit all keys, demonstrated in tests.


common/archiver/provider/init.go (1 line):
	- line 35: // TODO: ideally remove this and handle per-instance registration during startup somehow,


common/persistence/execution_manager.go (1 line):
	- line 89: ReplicationState:   response.State.ReplicationState, // TODO: remove this after all 2DC workflows complete


common/authorization/oauthAuthorizer.go (1 line):
	- line 65: TTL    int64 // TODO should be removed. ExpiresAt should be used


bench/lib/config.go (1 line):
	- line 62: // TODO: add comment for each config field


common/domain/dlqMessageHandler.go (1 line):
	- line 191: // TODO:


service/history/decision/checker.go (1 line):
	- line 341: // TODO: uncomment the following code when the client side bug for calculating scheduleToClose deadline is fixed and