> On Feb. 2, 2016, 1:43 a.m., Amareshwari Sriramadasu wrote: > > lens-server-api/src/main/java/org/apache/lens/server/api/driver/AbstractLensDriver.java, > > line 84 > > <https://reviews.apache.org/r/42067/diff/3/?file=1227565#file1227565line84> > > > > Returning null seems to be wrong implementation. Should the method be > > marked abstract instead?
Incase the driver uses its own fetch implementation, this method need not be implemented. So rather than making it abstract, I will instead throw an Exception from this method saying "Implementing driver should override this method if relying on default implmenattion of fetch". > On Feb. 2, 2016, 1:43 a.m., Amareshwari Sriramadasu wrote: > > lens-server-api/src/main/java/org/apache/lens/server/api/query/QueryContext.java, > > line 185 > > <https://reviews.apache.org/r/42067/diff/3/?file=1227568#file1227568line185> > > > > I'm thinking shall we use inmemory result ttl itself, instead of this ? Can change to this if it makes more sense. - Puneet ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/42067/#review117333 ----------------------------------------------------------- On Feb. 1, 2016, 7:19 a.m., Puneet Gupta wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/42067/ > ----------------------------------------------------------- > > (Updated Feb. 1, 2016, 7:19 a.m.) > > > Review request for lens. > > > Bugs: lens-901 > https://issues.apache.org/jira/browse/lens-901 > > > Repository: lens > > > Description > ------- > > support streaming results on lens > > > Diffs > ----- > > > lens-api/src/main/java/org/apache/lens/api/query/QueryHandleWithResultSet.java > a5da867 > lens-api/src/main/java/org/apache/lens/api/query/QueryStatus.java 44fd97e > lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveDriver.java > 149c6ab > lens-driver-jdbc/src/main/java/org/apache/lens/driver/jdbc/JDBCDriver.java > 82d7513 > > lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestJdbcDriver.java > b96cf88 > > lens-server-api/src/main/java/org/apache/lens/server/api/LensConfConstants.java > a3dbfc0 > > lens-server-api/src/main/java/org/apache/lens/server/api/driver/AbstractLensDriver.java > ed1fc43 > > lens-server-api/src/main/java/org/apache/lens/server/api/driver/InMemoryResultSet.java > c64a3dd > > lens-server-api/src/main/java/org/apache/lens/server/api/driver/PartiallyFetchedInMemoryResultSet.java > PRE-CREATION > > lens-server-api/src/main/java/org/apache/lens/server/api/query/QueryContext.java > 1269e45 > > lens-server/src/main/java/org/apache/lens/server/query/QueryExecutionServiceImpl.java > 672f2be > lens-server/src/main/resources/lenssession-default.xml a321c3f > lens-server/src/test/java/org/apache/lens/server/query/TestLensDAO.java > 01e846a > > lens-server/src/test/java/org/apache/lens/server/query/TestQueryService.java > 3facded > > lens-server/src/test/java/org/apache/lens/server/query/TestResultFormatting.java > 30d1e34 > src/site/apt/admin/config.apt 54f827e > src/site/apt/admin/session-config.apt 05a2c2c > > Diff: https://reviews.apache.org/r/42067/diff/ > > > Testing > ------- > > Three properties have been added to enable streaming > > * lens.query.prefetch.inmemory.resultset > When set to true, specified number of rows of in-memory result set will be > pre-fetched > > * lens.query.prefetch.inmemory.resultset.rows > Specifies the number of rows to pre-fetch for in-memory result set when > lens.query.prefetch.inmemory.resultset is set to true. Default value is 100 > rows. > > * lens.query.prefetch.inmemory.resultset.ttl.millis Specifies the time in > milli seconds starting from query submission time for which the pre-fetched > in-memory result set will not be purged. This property is put to action only > when lens.query.prefetch.inmemory.resultset is set to true and all rows of > the in memory result set have been pre-fetched. The default value of this > property is 60 secs. > > Streaming(pre-fetched) result set is available in case the above proerties > are set and the result is a type of InMemoryResultSet. Further, the streming > is enabled only when all result rows have been prefetched.Partial Streaming > not supported as of now (Can be enabled in furtue is there is a clear use > case for it) > > Also note QueryHandleWithResultSet will now hold result metadta > (QueryResultSetMetadata) also. > This info will be useful for client in case the streaming results are > accesesd via execute_with_timeout API (REST End Point /queryapi/queries POST ) > > It is suggested to use this feature for queries that finish fast and return > small number of rows. Streaming and persistence by server can happen > parallely for streamed result sets. > > Will add more details on **Testing** done . Was able to build and run > checkstyle. Also ran the added test cases for this feature. > > **TODO** PartiallyFetchedInMemoryResultSet can override > InMemoryResultSet.toQueryResult() and optimize the case where result has been > completely fetched already. > > > Thanks, > > Puneet Gupta > >
