HI Iceberg-devs We are trying to root cause issue where driver get stuck when trying to read comparatively large tables ( > 2000 snapshots)
When I tried to look at the thread dump of the driver's main thread I see that thread is stuck in planning tasks. I also noticed that iceberg-worker-pool is idle and mostly 1 thread is active. Has anyone faced a similar issue? what parameters can be used to optimize reads for tables with large number of snapshots ( with smaller data files) java.net.SocketInputStream.socketRead0(Native Method) java.net.SocketInputStream.socketRead(SocketInputStream.java:116) java.net.SocketInputStream.read(SocketInputStream.java:171) java.net.SocketInputStream.read(SocketInputStream.java:141) sun.security.ssl.InputRecord.readFully(InputRecord.java:465) sun.security.ssl.InputRecord.read(InputRecord.java:503) sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:990) => holding Monitor(java.lang.Object@580832623}) sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:948) sun.security.ssl.AppInputStream.read(AppInputStream.java:105) => holding Monitor(sun.security.ssl.AppInputStream@894541691}) org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:137) org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:153) org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:280) org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:138) org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56) org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259) org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:163) org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157) org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:273) com.amazonaws.http.protocol.SdkHttpRequestExecutor.doReceiveResponse(SdkHttpRequestExecutor.java:82) org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125) org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272) org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186) org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185) org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83) org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56) com.amazonaws.http.apache.client.impl.SdkHttpClient.execute(SdkHttpClient.java:72) com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1297) com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1113) com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:770) com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:744) com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:726) com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:686) com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:668) com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:532) com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:512) com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:4926) com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:4872) com.amazonaws.services.s3.AmazonS3Client.getObject(AmazonS3Client.java:1472) org.apache.hadoop.fs.s3a.S3AInputStream.reopen(S3AInputStream.java:148) org.apache.hadoop.fs.s3a.S3AInputStream.lazySeek(S3AInputStream.java:281) org.apache.hadoop.fs.s3a.S3AInputStream.read(S3AInputStream.java:364) => holding Monitor(org.apache.hadoop.fs.s3a.S3AInputStream@1577065760}) java.io.DataInputStream.read(DataInputStream.java:149) org.apache.iceberg.hadoop.HadoopStreams$HadoopSeekableInputStream.read(HadoopStreams.java:112) org.apache.iceberg.avro.AvroIO$AvroInputStreamAdapter.read(AvroIO.java:106) org.apache.iceberg.shaded.org.apache.avro.file.DataFileReader.openReader(DataFileReader.java:55) org.apache.iceberg.avro.AvroIterable.newFileReader(AvroIterable.java:94) org.apache.iceberg.avro.AvroIterable.getMetadata(AvroIterable.java:66) org.apache.iceberg.ManifestReader.<init>(ManifestReader.java:141) org.apache.iceberg.ManifestReader.read(ManifestReader.java:119) org.apache.iceberg.ManifestGroup.lambda$entries$13(ManifestGroup.java:212) org.apache.iceberg.ManifestGroup$$Lambda$89/1042679820.apply(Unknown Source) org.apache.iceberg.shaded.com.google.common.collect.Iterators$6.transform(Iterators.java:783) org.apache.iceberg.shaded.com.google.common.collect.TransformedIterator.next(TransformedIterator.java:47) org.apache.iceberg.shaded.com.google.common.collect.TransformedIterator.next(TransformedIterator.java:47) org.apache.iceberg.util.ParallelIterable$ParallelIterator.submitNextTask(ParallelIterable.java:113) org.apache.iceberg.util.ParallelIterable$ParallelIterator.checkTasks(ParallelIterable.java:100) org.apache.iceberg.util.ParallelIterable$ParallelIterator.hasNext(ParallelIterable.java:137) => holding Monitor(org.apache.iceberg.util.ParallelIterable$ParallelIterator@1724178871}) org.apache.iceberg.shaded.com.google.common.collect.TransformedIterator.hasNext(TransformedIterator.java:42) org.apache.iceberg.shaded.com.google.common.collect.TransformedIterator.hasNext(TransformedIterator.java:42) org.apache.iceberg.shaded.com.google.common.collect.Iterators$ConcatenatedIterator.getTopMetaIterator(Iterators.java:1309) org.apache.iceberg.shaded.com.google.common.collect.Iterators$ConcatenatedIterator.hasNext(Iterators.java:1325) org.apache.iceberg.util.BinPacking$PackingIterator.next(BinPacking.java:111) org.apache.iceberg.util.BinPacking$PackingIterator.next(BinPacking.java:87) org.apache.iceberg.io.CloseableIterable$3$1.next(CloseableIterable.java:94) org.apache.iceberg.shaded.com.google.common.collect.Iterators.addAll(Iterators.java:356) org.apache.iceberg.shaded.com.google.common.collect.Lists.newArrayList(Lists.java:143) org.apache.iceberg.shaded.com.google.common.collect.Lists.newArrayList(Lists.java:130) org.apache.iceberg.spark.source.Reader.tasks(Reader.java:295) org.apache.iceberg.spark.source.Reader.planInputPartitions(Reader.java:196) org.apache.spark.sql.execution.datasources.v2.DataSourceV2ScanExec.partitions$lzycompute(DataSourceV2ScanExec.scala:76) => holding Monitor(org.apache.spark.sql.execution.datasources.v2.DataSourceV2ScanExec@853913013}) org.apache.spark.sql.execution.datasources.v2.DataSourceV2ScanExec.partitions(DataSourceV2ScanExec.scala:75) org.apache.spark.sql.execution.datasources.v2.DataSourceV2ScanExec.outputPartitioning(DataSourceV2ScanExec.scala:65) -- Thanks
