Unpin threadpool core counts

Author: alexowens90

cpp/arcticdb/async/task_scheduler.hpp

@@ -179,10 +179,10 @@ class TaskScheduler {
     using CPUSchedulerType = folly::FutureExecutor<folly::CPUThreadPoolExecutor>;
     using IOSchedulerType = folly::FutureExecutor<folly::IOThreadPoolExecutor>;
 
-     explicit TaskScheduler(ARCTICDB_UNUSED const std::optional<size_t>& cpu_thread_count = std::nullopt, ARCTICDB_UNUSED const std::optional<size_t>& io_thread_count = std::nullopt) :
+     explicit TaskScheduler(const std::optional<size_t>& cpu_thread_count = std::nullopt, const std::optional<size_t>& io_thread_count = std::nullopt) :
         cgroup_folder_("/sys/fs/cgroup"),
-        cpu_thread_count_(1),
-        io_thread_count_(1),
+        cpu_thread_count_(cpu_thread_count ? *cpu_thread_count : ConfigsMap::instance()->get_int("VersionStore.NumCPUThreads", get_default_num_cpus(cgroup_folder_))),
+        io_thread_count_(io_thread_count ? *io_thread_count : ConfigsMap::instance()->get_int("VersionStore.NumIOThreads", (int) (cpu_thread_count_ * 1.5))),
         cpu_exec_(cpu_thread_count_, std::make_shared<InstrumentedNamedFactory>("CPUPool")) ,
         io_exec_(io_thread_count_,  std::make_shared<InstrumentedNamedFactory>("IOPool")){
         util::check(cpu_thread_count_ > 0 && io_thread_count_ > 0, "Zero IO or CPU threads: {} {}", io_thread_count_, cpu_thread_count_);

cpp/arcticdb/processing/clause.hpp

@@ -679,6 +679,8 @@ struct ConcatClause {
     ARCTICDB_MOVE_COPY_DEFAULT(ConcatClause)
 
     [[nodiscard]] std::vector<std::vector<size_t>> structure_for_processing(ARCTICDB_UNUSED std::vector<RangesAndKey>& ranges_and_keys) {
+        // TODO: This isn't a long term requirement, for simplicity at the moment we force all input symbols through their own
+        // processing pipeline right now, even if they have no clauses
         internal::raise<ErrorCode::E_ASSERTION_FAILURE>("ConcatClause should never be first in the pipeline");
     }