Todd Lipcon has submitted this change and it was merged. Change subject: log_block_manager: switch from google::sparse_hash_map to sparsepp ......................................................................
log_block_manager: switch from google::sparse_hash_map to sparsepp sparsepp is updated for C++11 so it enables move semantics for the map elements. Since the block map uses ref-counted values, being able to move them is a big win. It also claims to be generally faster even aside from the ability to support moves. According to [1] this data structure uses ~10% more memory than google::sparse_hash_map. However, previous measurement indicated that 1M blocks used about 9MB of memory, so this isn't a major consumer as far as the overall system is concerned. It seems worth a few extra MB of memory in order to make substantial startup time improvements. Despite slightly more memory usage, it's still significantly better than std::unordered_map, and also shares the benefit of avoiding any large allocations. (std::unordered_map needs a contiguous allocation for the buckets array). This patch alone improved startup time 7-8x on a real host with ~11M blocks: Before: I0907 17:23:50.748055 12507 fs_manager.cc:335] Time spent opening block manager: real 108.910s user 0.000s sys 0.001s After: I0907 17:20:42.277474 10021 fs_manager.cc:335] Time spent opening block manager: real 14.348s user 0.000s sys 0.001s The LBM startup benchmark (1M blocks) improved less substantially but still noticeably: Before: I0907 17:16:54.899818 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.612s user 0.035s sys 0.002s I0907 17:16:57.498205 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.598s user 0.039s sys 0.001s I0907 17:17:00.100244 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.602s user 0.042s sys 0.000s I0907 17:17:02.686638 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.586s user 0.042s sys 0.000s I0907 17:17:05.284050 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.597s user 0.041s sys 0.001s I0907 17:17:07.884395 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.600s user 0.039s sys 0.001s I0907 17:17:10.490550 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.606s user 0.040s sys 0.001s I0907 17:17:13.070114 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.580s user 0.039s sys 0.000s I0907 17:17:15.667062 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.597s user 0.040s sys 0.001s I0907 17:17:18.258447 20839 log_block_manager-test.cc:799] Time spent reopening block manager: real 2.591s user 0.042s sys 0.000s After: I0907 17:15:50.645310 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.570s user 0.034s sys 0.001s I0907 17:15:52.195543 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.550s user 0.037s sys 0.001s I0907 17:15:53.755209 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.560s user 0.037s sys 0.001s I0907 17:15:55.263762 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.509s user 0.038s sys 0.001s I0907 17:15:56.818748 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.555s user 0.037s sys 0.001s I0907 17:15:58.379680 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.561s user 0.036s sys 0.001s I0907 17:15:59.913751 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.534s user 0.038s sys 0.000s I0907 17:16:01.461668 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.548s user 0.037s sys 0.001s I0907 17:16:03.020823 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.559s user 0.037s sys 0.001s I0907 17:16:04.549747 20302 log_block_manager-test.cc:799] Time spent reopening block manager: real 1.529s user 0.035s sys 0.001s [1] https://github.com/greg7mdp/sparsepp/blob/master/bench.md Change-Id: I7397f9cd418782caecf8b2dae2c7bfe2c0e6215c Reviewed-on: http://gerrit.cloudera.org:8080/8007 Tested-by: Kudu Jenkins Reviewed-by: Adar Dembo <a...@cloudera.com> --- M src/kudu/fs/log_block_manager.h M thirdparty/build-definitions.sh M thirdparty/build-thirdparty.sh M thirdparty/download-thirdparty.sh M thirdparty/vars.sh 5 files changed, 35 insertions(+), 2 deletions(-) Approvals: Adar Dembo: Looks good to me, approved Kudu Jenkins: Verified -- To view, visit http://gerrit.cloudera.org:8080/8007 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: merged Gerrit-Change-Id: I7397f9cd418782caecf8b2dae2c7bfe2c0e6215c Gerrit-PatchSet: 3 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon <t...@apache.org> Gerrit-Reviewer: Adar Dembo <a...@cloudera.com> Gerrit-Reviewer: Dan Burkert <danburk...@apache.org> Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Tidy Bot Gerrit-Reviewer: Todd Lipcon <t...@apache.org>
