Improve defaults for benchmarks

Summary:
Changes include:
* don't sync-on-commit for single writer thread in readwhile... tests
* make default block size 8kb rather than 4kb to avoid too small blocks after compression
* use snappy instead of zlib to avoid stalls from compression latency
* disable statistics
* use bytes_per_sync=8M to reduce throughput loss on disk
* use open_files=-1 to reduce mutex contention

Task ID: #

Blame Rev:

Test Plan:
run benchmark

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44961

tools/benchmark.sh

@@ -47,7 +47,7 @@ duration=${DURATION:-0}
 num_keys=${NUM_KEYS:-$((1 * G))}
 key_size=20
 value_size=${VALUE_SIZE:-400}
-block_size=${BLOCK_SIZE:-4096}
+block_size=${BLOCK_SIZE:-8192}
 
 const_params="
   --db=$DB_DIR \
@@ -61,11 +61,12 @@ const_params="
   --block_size=$block_size \
   --cache_size=$cache_size \
   --cache_numshardbits=6 \
-  --compression_type=zlib \
+  --compression_type=snappy \
   --min_level_to_compress=3 \
   --compression_ratio=0.5 \
   --level_compaction_dynamic_level_bytes=true \
-  --bytes_per_sync=$((2 * M)) \
+  --bytes_per_sync=$((8 * M)) \
+  --cache_index_and_filter_blocks=0 \
   \
   --hard_rate_limit=3 \
   --rate_limit_delay_max_milliseconds=1000000 \
@@ -79,14 +80,14 @@ const_params="
   --max_grandparent_overlap_factor=8 \
   --max_bytes_for_level_multiplier=8 \
   \
-  --statistics=1 \
+  --statistics=0 \
   --stats_per_interval=1 \
   --stats_interval_seconds=60 \
   --histogram=1 \
   \
   --memtablerep=skip_list \
   --bloom_bits=10 \
-  --open_files=$((20 * K))"
+  --open_files=-1"
 
 l0_config="
   --level0_file_num_compaction_trigger=4 \

tools/run_flash_bench.sh

@@ -62,7 +62,7 @@ duration=${NSECONDS:-$((60 * 60))}
 nps=${RANGE_LIMIT:-10}
 vs=${VAL_SIZE:-400}
 cs=${CACHE_BYTES:-$(( 1 * G ))}
-bs=${BLOCK_LENGTH:-4096}
+bs=${BLOCK_LENGTH:-8192}
 
 # If no command line arguments then run for 24 threads.
 if [[ $# -eq 0 ]]; then
@@ -193,15 +193,15 @@ for num_thr in "${nthreads[@]}" ; do
 
   # Test 11: random read while writing
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
-    ./tools/benchmark.sh readwhilewriting
+    DB_BENCH_NO_SYNC=1 ./tools/benchmark.sh readwhilewriting
 
   # Test 12: range scan while writing
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
-    NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh fwdrangewhilewriting
+    DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh fwdrangewhilewriting
 
   # Test 13: reverse range scan while writing
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
-    NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh revrangewhilewriting
+    DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh revrangewhilewriting
 done
 
 ###### Merge tests
@@ -216,15 +216,15 @@ for num_thr in "${nthreads[@]}" ; do
 
   # Test 16: random read while merging 
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
-    ./tools/benchmark.sh readwhilemerging
+    DB_BENCH_NO_SYNC=1 ./tools/benchmark.sh readwhilemerging
 
   # Test 17: range scan while merging 
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
-    NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh fwdrangewhilemerging
+    DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh fwdrangewhilemerging
 
   # Test 18: reverse range scan while merging 
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
-    NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh revrangewhilemerging
+    DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh revrangewhilemerging
 done
 
 echo bulkload > $output_dir/report2.txt