[
https://issues.apache.org/jira/browse/HBASE-9426?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13759755#comment-13759755
]
Richard Ding commented on HBASE-9426:
-------------------------------------
Even with multiple internal procedures, the general approach can make region
server (and master) code cleaner and simpler. For instance we need four lines
of code in HRegionServer:
{code}
rspmHost.loadProcedures(conf);
rspmHost.initialize(this);
{code}
{code}
rspmHost.start();
{code}
{code}
rspmHost.stop(this.abortRequested || this.killed);
{code}
where rspm stands for _RegionServerProcedureManager_.
And the procedure managers are added in rspmHost.loadProcedures(conf) method:
{code}
loadSystemProcedures(conf, REGIONSERVER_PROCEUDRE_CONF_KEY);
// load the default snapshot manager
procedures.add(new RegionServerSnapshotManager());
procedures.add(new RegionServerLogRollManager()); // assume we have
implemented this class
procedures.add(new RegionServerFlushManager()); // assume we have
implemented this class
{code}
This way we don't need to add new code to HRegionServer for new procedure
implementations.
> Make custom distributed barrier procedure pluggable
> ----------------------------------------------------
>
> Key: HBASE-9426
> URL: https://issues.apache.org/jira/browse/HBASE-9426
> Project: HBase
> Issue Type: Improvement
> Affects Versions: 0.95.2, 0.94.11
> Reporter: Richard Ding
> Assignee: Richard Ding
>
> Currently if one wants to implement a custom distributed barrier procedure
> (e.g., distributed log roll or distributed table flush), the HBase core code
> needs to be modified in order for the procedure to work.
> Looking into the snapshot code (especially on region server side), most of
> the code to enable the procedure are generic life-cycle management (i.e.,
> init, start, stop). We can make this part pluggable.
> Here is the proposal. Following the coprocessor example, we define two
> properties:
> {code}
> hbase.procedure.regionserver.classes
> hbase.procedure.master.classes
> {code}
> The values for both are comma delimited list of classes. On region server
> side, the classes implements the following interface:
> {code}
> public interface RegionServerProcedureManager {
> public void initialize(RegionServerServices rss) throws KeeperException;
> public void start();
> public void stop(boolean force) throws IOException;
> public String getProcedureName();
> }
> {code}
> While on Master side, the classes implement the interface:
> {code}
> public interface MasterProcedureManager {
> public void initialize(MasterServices master) throws KeeperException,
> IOException, UnsupportedOperationException;
> public void stop(String why);
> public String getProcedureName();
> public void execProcedure(ProcedureDescription desc) throws IOException;
> IOException;
> }
> {code}
> Where the ProcedureDescription is defined as
> {code}
> message ProcedureDescription {
> required string name = 1;
> required string instance = 2;
> optional int64 creationTime = 3 [default = 0];
> message Property {
> required string tag = 1;
> optional string value = 2;
> }
> repeated Property props = 4;
> }
> {code}
> A generic API can be defined on HMaster to trigger a procedure:
> {code}
> public boolean execProcedure(ProcedureDescription desc) throws IOException;
> {code}
> _SnapshotManager_ and _RegionServerSnapshotManager_ are special examples of
> _MasterProcedureManager_ and _RegionServerProcedureManager_. They will be
> automatically included (users don't need to specify them in the conf file).
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
