Bug #28653 Fast GCP + high load + high RedoBuffer causes ndbrequire

- correction, use recomputed _actual_ redobuffer

ndb/src/kernel/blocks/dblqh/Dblqh.hpp

@@ -2668,7 +2668,8 @@ private:
   UintR cfirstfreeLogFile;
   UintR clogFileFileSize;
 
-#define ZLFO_FILE_SIZE 256            /* MAX 256 OUTSTANDING FILE OPERATIONS */
+#define ZLFO_MIN_FILE_SIZE 256
+// RedoBuffer/32K minimum ZLFO_MIN_FILE_SIZE
   LogFileOperationRecord *logFileOperationRecord;
   LogFileOperationRecordPtr lfoPtr;
   UintR cfirstfreeLfo;
@@ -2685,7 +2686,7 @@ private:
   UintR cfirstfreePageRef;
   UintR cpageRefFileSize;
 
-#define ZSCANREC_FILE_SIZE 100
+// Configurable
   ArrayPool<ScanRecord> c_scanRecordPool;
   ScanRecordPtr scanptr;
   UintR cscanNoFreeRec;

ndb/src/kernel/blocks/dblqh/DblqhInit.cpp

@@ -32,11 +32,11 @@ void Dblqh::initData()
   chostFileSize = MAX_NDB_NODES;
   clcpFileSize = ZNO_CONCURRENT_LCP;
   clcpLocrecFileSize = ZLCP_LOCREC_FILE_SIZE;
-  clfoFileSize = ZLFO_FILE_SIZE;
+  clfoFileSize = 0;
   clogFileFileSize = 0;
   clogPartFileSize = ZLOG_PART_FILE_SIZE;
   cpageRefFileSize = ZPAGE_REF_FILE_SIZE;
-  cscanrecFileSize = ZSCANREC_FILE_SIZE;
+  cscanrecFileSize = 0;
   ctabrecFileSize = 0;
   ctcConnectrecFileSize = 0;
   ctcNodeFailrecFileSize = MAX_NDB_NODES;

ndb/src/kernel/blocks/dblqh/DblqhMain.cpp

@@ -7251,6 +7251,11 @@ void Dblqh::continueScanNextReqLab(Signal* signal)
     return;
   }
 
+  /* maximum number of log file operations */
+  clfoFileSize = clogPageFileSize;
+  if (clfoFileSize < ZLFO_MIN_FILE_SIZE)
+    clfoFileSize = ZLFO_MIN_FILE_SIZE;
+
   // Update timer on tcConnectRecord
   tcConnectptr.p->tcTimer = cLqhTimeOutCount;
   init_acc_ptr_list(scanptr.p);