Add an option for parallel compression in for db_stress (#6722)

Summary:
This commit adds an `compression_parallel_threads` option in
db_stress. It also fixes the naming of parallel compression
option in db_bench to keep it aligned with others.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6722

Reviewed By: pdillinger

Differential Revision: D21091385

fbshipit-source-id: c9ba8c4e5cc327ff9e6094a6dc6a15fcff70f100

db_stress_tool/db_stress_common.h

@@ -201,6 +201,7 @@ DECLARE_string(compression_type);
 DECLARE_string(bottommost_compression_type);
 DECLARE_int32(compression_max_dict_bytes);
 DECLARE_int32(compression_zstd_max_train_bytes);
+DECLARE_int32(compression_parallel_threads);
 DECLARE_string(checksum_type);
 DECLARE_string(hdfs);
 DECLARE_string(env_uri);

db_stress_tool/db_stress_gflags.cc

@@ -584,6 +584,9 @@ DEFINE_int32(compression_zstd_max_train_bytes, 0,
              "Maximum size of training data passed to zstd's dictionary "
              "trainer.");
 
+DEFINE_int32(compression_parallel_threads, 1,
+             "Number of threads for parallel compression.");
+
 DEFINE_string(bottommost_compression_type, "disable",
               "Algorithm to use to compress bottommost level of the database. "
               "\"disable\" means disabling the feature");

db_stress_tool/db_stress_test_base.cc

@@ -1803,6 +1803,8 @@ void StressTest::Open() {
     options_.compression_opts.max_dict_bytes = FLAGS_compression_max_dict_bytes;
     options_.compression_opts.zstd_max_train_bytes =
         FLAGS_compression_zstd_max_train_bytes;
+    options_.compression_opts.parallel_threads =
+        FLAGS_compression_parallel_threads;
     options_.create_if_missing = true;
     options_.max_manifest_file_size = FLAGS_max_manifest_file_size;
     options_.inplace_update_support = FLAGS_in_place_update;

tools/db_bench_tool.cc

@@ -926,8 +926,8 @@ DEFINE_int32(min_level_to_compress, -1, "If non-negative, compression starts"
              " not compressed. Otherwise, apply compression_type to "
              "all levels.");
 
-DEFINE_int32(compression_threads, 1,
+DEFINE_int32(compression_parallel_threads, 1,
-             "Number of concurrent compression threads to run.");
+             "Number of threads for parallel compression.");
 
 static bool ValidateTableCacheNumshardbits(const char* flagname,
                                            int32_t value) {
@@ -4030,7 +4030,8 @@ class Benchmark {
     options.compression_opts.max_dict_bytes = FLAGS_compression_max_dict_bytes;
     options.compression_opts.zstd_max_train_bytes =
         FLAGS_compression_zstd_max_train_bytes;
-    options.compression_opts.parallel_threads = FLAGS_compression_threads;
+    options.compression_opts.parallel_threads =
+        FLAGS_compression_parallel_threads;
     // If this is a block based table, set some related options
     if (options.table_factory->Name() == BlockBasedTableFactory::kName &&
         options.table_factory->GetOptions() != nullptr) {

tools/db_crashtest.py

@@ -44,6 +44,7 @@ default_params = {
     "checksum_type" : lambda: random.choice(["kCRC32c", "kxxHash", "kxxHash64"]),
     "compression_max_dict_bytes": lambda: 16384 * random.randint(0, 1),
     "compression_zstd_max_train_bytes": lambda: 65536 * random.randint(0, 1),
+    "compression_parallel_threads": lambda: random.choice([1] * 9 + [4]),
     "clear_column_family_one_in": 0,
     "compact_files_one_in": 1000000,
     "compact_range_one_in": 1000000,