* Introduce Group interface and AllGroup
As we move towards consumer groups we'll need to support the current
"consume all shards" strategy, and setup the codebase for the
anticipated "consume balanced shards."
Having consumers start at latest record seems like a reasonable default.
This can also be overridden with optional config, make sure that is
documented for users of the library.
Fixes: https://github.com/harlow/kinesis-consumer/issues/86
* Use shard broker to start processing new shards
The addition of a shard broker will allow the consumer to be notified
when new shards are added to the stream so it can consume them.
Fixes: https://github.com/harlow/kinesis-consumer/issues/36
Major changes:
```go
type ScanFunc func(r *Record) error
```
* Simplify the callback func signature by removing `ScanStatus`
* Leverage context for cancellation
* Add custom error `SkipCheckpoint` for special cases when we don't want to checkpoint
Minor changes:
* Use kinesis package constants for shard iterator types
* Move optional config to new file
See conversation on #75 for more details
Changes:
* I add postgres_databaseutils_test.go for containing all utilities for mocking the database.
* I put appName as a required parameter passed to the New() since it is needed to form the namespace column name.
* I add GetMaxInterval() since it might be needed by the consumer and the test.
* I move the SQL string package variables directly into the function that need it so we could avoid maintenance nightmare in the future.
Having an additional Client has added some confusion (https://github.com/harlow/kinesis-consumer/issues/45) on how to provide a
custom kinesis client. Allowing `WithClient` to accept a Kinesis client
it cleans up the interface.
Major changes:
* Remove the Client wrapper; prefer using kinesis client directly
* Change `ScanError` to `ScanStatus` as the return value isn't necessarily an error
Note: these are breaking changes, if you need last stable release please see here: https://github.com/harlow/kinesis-consumer/releases/tag/v0.2.0
A closed shard returns the last sequence number and no error. The current implementation leads to an infinite loop if the shard is closed. NextShardIterator checking is enough. That's why I remove the getShardIterator call
- scanError.Error is removed since it is not used.
- session.New() is deprecated, The NewKinesisClient's function signature change so it can
returns the error from the NewSession().
* remove ValidateCheckpoint
* update for checkpoint can not customize retryer
* implement the scan error as in PR 44
* at least log if record processor has error
* mistakenly removed this line
* propage error up. ignore invalid state
Add interval flush for DDB checkpoint
* Allow checkpointing on a specified interval
* Add shutdown method to checkpoint to force flush
Minor changes:
* Swap order of input params for checkpoint (app, table)
Addresses: https://github.com/harlow/kinesis-consumer/issues/39
Testing the components of the consumer where proving difficult because
the consumer code was so tightly coupled with the Kinesis client
library.
* Extract the concept of Client interface
* Create default client w/ kinesis connection
* Test with fake client to avoid round trip to kinesis
