n3nash commented on a change in pull request #2440: URL: https://github.com/apache/hudi/pull/2440#discussion_r558822909
########## File path: hudi-common/src/main/java/org/apache/hudi/common/table/log/HoodieLogFileReader.java ########## @@ -274,19 +275,27 @@ private boolean isBlockCorrupt(int blocksize) throws IOException { } private long scanForNextAvailableBlockOffset() throws IOException { + // Make buffer large enough to scan through the file as quick as possible especially if it is on S3/GCS. + // Using lower buffer is incurring a lot of API calls thus drastically increasing the cost of the storage + // and also may take days to complete scanning trough the large files. + byte[] dataBuf = new byte[1024 * 1024]; Review comment: @vburenin According to the current code, we still are using BufferedReader for all cases except GCS, so that doesn't go away with this code in a generic way. Additionally, we need buffered reader code (the one I pointed above) anyways for GCS in the happy code path (without the need to find the magic header in corrupt blocks) since this method is only called when it encounters a corrupt block. 1) readFully does a bunch of if conditions so branching could cause some perf degradation here, don't see any other extra logic apart from copying bytes which is the same for irrespective of doing 6 bytes vs 1MB 2) Position modification in BufferedInputStream is a variable assignment which should not cause any overhead. Agree with you that the best number should be the one that matches the underlying block size. It would be great if you can do some microbenchmarking here. I'm OK to land this once you can add the if check for BufferedInputStream since that is needed anyways ? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org