Thank you for your feedback. Forward compatibility is required:
1. Get CursorInfo from the metadata store: We will check the cursor data header, if it is compressed, we will parse the bytes data by compressed format, otherwise we will parse the cursor data directly by the original way. 2. Add/Update CursorInfo to the metadata store: The default is to use compression if the compression type is specified, otherwise we will put this data to the metadata store directly. > 2022年3月2日 下午11:48，Zike Yang <zky...@streamnative.io.INVALID> 写道： > > Hi, Zixuan > Thanks for creating this PIP. Here are my thoughts. > >> CursorInfo compression format >> >> [MAGIC_NUMBER] + [METADATA_SIZE] + [METADATA_PAYLOAD] + >> [MANAGED_CURSOR_INFO_PAYLOAD] >> >> MAGIC_NUMBER: Ox4779 > > Since we change the ManagedCursorInfo data format here. How do we > handle the old data format in the ZK. Could you explain the > compatibility for this PIP? > > Thanks, > Zike Yang > > On Wed, Mar 2, 2022 at 3:34 PM Zixuan Liu <node...@gmail.com > <mailto:node...@gmail.com>> wrote: >> >> Hi Pulsar Community, >> >> I create a proposal that ManagedCursorInfo compression. The proposal can be >> found: https://github.com/apache/pulsar/issues/14529 >> <https://github.com/apache/pulsar/issues/14529> >> <https://github.com/apache/pulsar/issues/14529 >> <https://github.com/apache/pulsar/issues/14529>> >> >> Thanks, >> Zixuan >> >> ------------------ >> >> Motivation >> >> The cursor data is managed by ZooKeeper/etcd metadata store. When cursor >> data becomes more and more, the data size will increase and will take a lot >> of time to pull the data. Therefore, it is necessary to add compression for >> the cursor, which can reduce the size of data and reduce the time of pulling >> data. >> >> Goal >> >> Support use the LZ4/ZLIB/ZSTD/SNAPPY to compress the ManagedCursorInfo. >> >> Implementation >> >> CursorInfo compression format >> >> [MAGIC_NUMBER] + [METADATA_SIZE] + [METADATA_PAYLOAD] + >> [MANAGED_CURSOR_INFO_PAYLOAD] >> >> MAGIC_NUMBER: Ox4779 >> >> METADATA >> Add a named ManagedCursorInfoMetadata message to MLDataFormats.proto >> >> message ManagedCursorInfoMetadata { >> required CompressionType compressionType = 1; >> required int32 uncompressedSize = 2; >> } >> CursorInfo compression and decompression design >> >> Currently, these compressions types have been defined and implemented by >> Pulsar, we only need to deal with compression and decompression of the >> ManagedCursorInfo data: >> >> Get CursorInfo from the metadata store >> We will check the cursor data header, if it is compressed, we will parse the >> bytes data by compressed format, otherwise by the original way. >> >> Add/Update CursorInfo to the metadata store >> The default is to use compression if the compression type is specified. >> >> CursorInfo compression type configuration >> >> Add managedCursorInfoCompressionType in >> org.apache.pulsar.broker.ServiceConfiguration and >> org.apache.bookkeeper.mledger.ManagedLedgerFactoryConfig. >> >> > > > -- > Zike Yang
