empiredan commented on a change in pull request #646:
URL: https://github.com/apache/incubator-pegasus/pull/646#discussion_r530149511
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File path: src/server/pegasus_server_impl_init.cpp
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@@ -299,6 +300,130 @@
pegasus_server_impl::pegasus_server_impl(dsn::replication::replica *r)
_db_opts.rate_limiter = _s_rate_limiter;
}
+ bool enable_write_buffer_manager = dsn_config_get_value_bool(
+ "pegasus.server",
+ "rocksdb_enable_write_buffer_manager",
+ false,
+ "enable write buffer manager to limit total memory "
+ "used by memtables and block caches across multiple replicas");
+ ddebug("rocksdb_enable_write_buffer_manager = %d",
enable_write_buffer_manager);
+ if (enable_write_buffer_manager) {
+ // If write buffer manager is enabled, all replicas(one DB instance
for each
+ // replica) on this server will share the same write buffer manager
object,
+ // thus the same block cache object. It's convenient to control the
total memory
+ // of memtables and bloack caches used by this server
+ static std::once_flag flag;
+ std::call_once(flag, [&]() {
+ int64_t total_size_across_write_buffer =
dsn_config_get_value_int64(
+ "pegasus.server",
+ "rocksdb_total_size_across_write_buffer",
+ 0,
+ "total size limit used by memtables across multiple
replicas");
+ ddebug("rocksdb_total_size_across_write_buffer = %" PRId64,
total_size_across_write_buffer);
+ if (total_size_across_write_buffer < 0) {
+ total_size_across_write_buffer = 0;
+ }
+ _s_write_buffer_manager =
std::make_shared<rocksdb::WriteBufferManager>(
+ static_cast<size_t>(total_size_across_write_buffer),
tbl_opts.block_cache);
+ });
+ _db_opts.write_buffer_manager = _s_write_buffer_manager;
+ }
+
+ int64_t max_open_files = dsn_config_get_value_int64(
+ "pegasus.server",
+ "rocksdb_max_open_files",
+ -1,
+ "number of open files that can be used by a replica(namely a DB
instance)");
+ _db_opts.max_open_files = static_cast<int>(max_open_files);
+ ddebug("rocksdb_max_open_files = %d", _db_opts.max_open_files);
+
+ std::string index_type = dsn_config_get_value_string(
+ "pegasus.server",
+ "rocksdb_index_type",
+ "kBinarySearch",
+ "The index type that will be used for this table.");
+ const std::unordered_map<std::string,
rocksdb::BlockBasedTableOptions::IndexType>
+ index_type_string_map = {
+ {"kBinarySearch",
rocksdb::BlockBasedTableOptions::IndexType::kBinarySearch},
+ {"kHashSearch",
rocksdb::BlockBasedTableOptions::IndexType::kHashSearch},
+ {"kTwoLevelIndexSearch",
+ rocksdb::BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch},
+ {"kBinarySearchWithFirstKey",
+ rocksdb::BlockBasedTableOptions::IndexType::kBinarySearchWithFirstKey}
+ };
+ auto index_type_item = index_type_string_map.find(index_type);
+ dassert(index_type_item != index_type_string_map.end(),
+ "[pegasus.server]rocksdb_index_type shold be one among
kBinarySearch, "
+ "kHashSearch, kTwoLevelIndexSearch or kBinarySearchWithFirstKey.");
+ tbl_opts.index_type = index_type_item->second;
+ ddebug("rocksdb_index_type = %s", index_type.c_str());
Review comment:
Actually, since I'd decided to cache index and filter blocks, I just
took this opportunity to involve partitioned indexes in. However we've been
developing pegasus based on v1.12.3, whose rocksdb's version is 5.9.2 and not
high enough to support index and filter blocks cached well. After several
related core-dumps had happened we had to disable all the options about the
cache and partitioned indexes. Until I saw the version of rocksdb used by
latest pegasus had reached 6.6.4, I thought those options could be enabled
again albeit disabled still by default. Unfortunately we've not done any
performance test since. I think these options should be enabled by users if
necessary
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