Expose counter for disconnects due to chunk timeout

Summary:
Add counter for FSDB stream client disconnect due to chunk timeout
with suffix: disconnectReason.chunkTimeout

Differential Revision: D64444138

fbshipit-source-id: 34a9751262e349d6c2ef2fe728d8722695b4ea9a

fboss/fsdb/client/FsdbStreamClient.cpp

@@ -124,6 +124,14 @@ folly::coro::Task<void> FsdbStreamClient::serviceLoopWrapper() {
                      << apache::thrift::util::enumNameSafe(ef.get_errorCode())
                      << ": " << ef.get_message();
     setStateDisconnectedWithReason(ef.get_errorCode());
+  } catch (const apache::thrift::transport::TTransportException& et) {
+    FsdbErrorCode disconnectReason = FsdbErrorCode::CLIENT_TRANSPORT_EXCEPTION;
+    if (et.getType() ==
+        apache::thrift::transport::TTransportException::
+            TTransportExceptionType::TIMED_OUT) {
+      disconnectReason = FsdbErrorCode::CLIENT_CHUNK_TIMEOUT;
+    }
+    setStateDisconnectedWithReason(disconnectReason);
   } catch (const std::exception& ex) {
     STREAM_XLOG(ERR) << "Unknown error: " << folly::exceptionStr(ex);
     setStateDisconnectedWithReason(FsdbErrorCode::DISCONNECTED);

fboss/fsdb/client/FsdbStreamClient.h

@@ -138,6 +138,9 @@ class FsdbStreamClient : public ReconnectingThriftClient {
  private:
   void updateDisconnectReasonCounter(fsdb::FsdbErrorCode reason) {
     switch (reason) {
+      case fsdb::FsdbErrorCode::CLIENT_CHUNK_TIMEOUT:
+        disconnectReasonChunkTimeout_.add(1);
+        break;
       case fsdb::FsdbErrorCode::SUBSCRIPTION_DATA_CALLBACK_ERROR:
         disconnectReasonDataCbError_.add(1);
         break;
@@ -150,6 +153,11 @@ class FsdbStreamClient : public ReconnectingThriftClient {
   std::atomic<bool> serviceLoopRunning_{false};
   const bool isStats_;
   apache::thrift::RpcOptions rpcOptions_;
+  // counters for various disconnect reasons
+  fb303::TimeseriesWrapper disconnectReasonChunkTimeout_{
+      getCounterPrefix() + ".disconnectReason.chunkTimeout",
+      fb303::SUM,
+      fb303::RATE};
   fb303::TimeseriesWrapper disconnectReasonDataCbError_{
       getCounterPrefix() + ".disconnectReason.dataCbError",
       fb303::SUM,

fboss/fsdb/if/fsdb_common.thrift

@@ -46,6 +46,8 @@ enum FsdbErrorCode {
   PUBLISHER_GR_DISCONNECT = 16,
   SUBSCRIPTION_NOT_PERMITTED = 17,
   SUBSCRIPTION_DATA_CALLBACK_ERROR = 18,
+  CLIENT_CHUNK_TIMEOUT = 19,
+  CLIENT_TRANSPORT_EXCEPTION = 20,
 }
 
 exception FsdbException {