NDB dbtux scan batch max 16->992 caused perf loss

ndb/src/kernel/blocks/dbtux/Dbtux.hpp

@@ -404,8 +404,6 @@ private:
     Uint32 m_savePointId;
     // lock waited for or obtained and not yet passed to LQH
     Uint32 m_accLockOp;
-    // locks obtained and passed to LQH but not yet returned by LQH
-    Uint32 m_accLockOps[MaxAccLockOps];
     Uint8 m_readCommitted;      // no locking
     Uint8 m_lockMode;
     Uint8 m_keyInfo;
@@ -421,6 +419,13 @@ private:
     Uint32 nextList;
     };
     Uint32 prevList;
+    /*
+     * Locks obtained and passed to LQH but not yet returned by LQH.
+     * The max was increased from 16 to 992 (default 64).  Record max
+     * ever used in this scan.  TODO fix quadratic behaviour
+     */
+    Uint32 m_maxAccLockOps;
+    Uint32 m_accLockOps[MaxAccLockOps];
     ScanOp(ScanBoundPool& scanBoundPool);
   };
   typedef Ptr<ScanOp> ScanOpPtr;
@@ -1028,15 +1033,18 @@ Dbtux::ScanOp::ScanOp(ScanBoundPool& scanBoundPool) :
   m_boundMax(scanBoundPool),
   m_scanPos(),
   m_scanEnt(),
-  m_nodeScan(RNIL)
+  m_nodeScan(RNIL),
+  m_maxAccLockOps(0)
 {
   m_bound[0] = &m_boundMin;
   m_bound[1] = &m_boundMax;
   m_boundCnt[0] = 0;
   m_boundCnt[1] = 0;
+#ifdef VM_TRACE
   for (unsigned i = 0; i < MaxAccLockOps; i++) {
-    m_accLockOps[i] = RNIL;
+    m_accLockOps[i] = 0x1f1f1f1f;
   }
+#endif
 }
 
 // Dbtux::Index

ndb/src/kernel/blocks/dbtux/DbtuxScan.cpp

@@ -917,7 +917,7 @@ Dbtux::scanClose(Signal* signal, ScanOpPtr scanPtr)
   ScanOp& scan = *scanPtr.p;
   ndbrequire(! scan.m_lockwait && scan.m_accLockOp == RNIL);
   // unlock all not unlocked by LQH
-  for (unsigned i = 0; i < MaxAccLockOps; i++) {
+  for (unsigned i = 0; i < scan.m_maxAccLockOps; i++) {
     if (scan.m_accLockOps[i] != RNIL) {
       jam();
       AccLockReq* const lockReq = (AccLockReq*)signal->getDataPtrSend();
@@ -947,7 +947,7 @@ Dbtux::addAccLockOp(ScanOp& scan, Uint32 accLockOp)
   ndbrequire(accLockOp != RNIL);
   Uint32* list = scan.m_accLockOps;
   bool ok = false;
-  for (unsigned i = 0; i < MaxAccLockOps; i++) {
+  for (unsigned i = 0; i < scan.m_maxAccLockOps; i++) {
     ndbrequire(list[i] != accLockOp);
     if (! ok && list[i] == RNIL) {
       list[i] = accLockOp;
@@ -955,6 +955,14 @@ Dbtux::addAccLockOp(ScanOp& scan, Uint32 accLockOp)
       // continue check for duplicates
     }
   }
+  if (! ok) {
+    unsigned i = scan.m_maxAccLockOps;
+    if (i < MaxAccLockOps) {
+      list[i] = accLockOp;
+      ok = true;
+      scan.m_maxAccLockOps = i + 1;
+    }
+  }
   ndbrequire(ok);
 }
 
@@ -964,7 +972,7 @@ Dbtux::removeAccLockOp(ScanOp& scan, Uint32 accLockOp)
   ndbrequire(accLockOp != RNIL);
   Uint32* list = scan.m_accLockOps;
   bool ok = false;
-  for (unsigned i = 0; i < MaxAccLockOps; i++) {
+  for (unsigned i = 0; i < scan.m_maxAccLockOps; i++) {
     if (list[i] == accLockOp) {
       list[i] = RNIL;
       ok = true;

ndb/src/kernel/blocks/dbtux/Times.txt

@@ -13,7 +13,7 @@ case c: full scan: index on PK Unsigned
 testOIBasic -case v -table 1 -index 1 -fragtype small -threads 10 -rows 100000 -subloop 1 -nologging
 
 case d: scan 1 tuple via EQ: index on PK Unsigned
-testOIBasic -case w -table 1 -index 1 -fragtype small -threads 10 -rows 100000 -samples 10000 -subloop 1 -nologging -v2
+testOIBasic -case w -table 1 -index 1 -fragtype small -threads 10 -rows 100000 -samples 50000 -subloop 1 -nologging -v2
 
 a, b
 1 million rows, pk update without index, pk update with index
@@ -132,4 +132,12 @@ optim 17        mc02/a  35 ms   52 ms    49 pct
 wl-1942         mc02/a  35 ms   52 ms    49 pct
                 mc02/b  42 ms   75 ms    76 pct
 
+before          mc02/c   5 ms   13 ms   126 pct
+                mc02/d 134 ms  238 ms    78 pct
+
+after           mc02/c   5 ms   10 ms    70 pct
+                mc02/d 178 ms  242 ms    69 pct
+
+[ prelim preformance fix for max batch size 16 -> 992 ]
+
 vim: set et:

ndb/test/ndbapi/testOIBasic.cpp

@@ -54,6 +54,7 @@ struct Opt {
   unsigned m_samples;
   unsigned m_scanbat;
   unsigned m_scanpar;
+  unsigned m_scanstop;
   unsigned m_seed;
   unsigned m_subloop;
   const char* m_table;
@@ -80,6 +81,7 @@ struct Opt {
     m_samples(0),
     m_scanbat(0),
     m_scanpar(0),
+    m_scanstop(0),
     m_seed(0),
     m_subloop(4),
     m_table(0),
@@ -708,6 +710,7 @@ struct Con {
   int nextScanResult(bool fetchAllowed, bool& deadlock);
   int updateScanTuple(Con& con2);
   int deleteScanTuple(Con& con2);
+  void closeScan();
   void closeTransaction();
   void printerror(NdbOut& out);
 };
@@ -894,12 +897,22 @@ Con::deleteScanTuple(Con& con2)
   return 0;
 }
 
+void
+Con::closeScan()
+{
+  assert(m_resultset != 0);
+  m_resultset->close();
+  m_scanop = 0, m_indexscanop = 0, m_resultset = 0;
+
+}
+
 void
 Con::closeTransaction()
 {
   assert(m_ndb != 0 && m_tx != 0);
   m_ndb->closeTransaction(m_tx);
   m_tx = 0, m_op = 0;
+  m_scanop = 0, m_indexscanop = 0, m_resultset = 0;
 }
 
 void
@@ -2538,6 +2551,10 @@ scanupdatetable(Par par)
       LL1("scanupdatetable: stop on deadlock");
       break;
     }
+    if (par.m_scanstop != 0 && urandom(par.m_scanstop) == 0) {
+      con.closeScan();
+      break;
+    }
     do {
       unsigned i = (unsigned)-1;
       CHK(set2.getkey(par, &i) == 0);
@@ -2618,6 +2635,10 @@ scanupdateindex(Par par, const ITab& itab, const BSet& bset)
       LL1("scanupdateindex: stop on deadlock");
       break;
     }
+    if (par.m_scanstop != 0 && urandom(par.m_scanstop) == 0) {
+      con.closeScan();
+      break;
+    }
     do {
       unsigned i = (unsigned)-1;
       CHK(set2.getkey(par, &i) == 0);
@@ -2782,6 +2803,7 @@ mixedoperations(Par par)
 {
   par.m_dups = true;
   par.m_deadlock = true;
+  par.m_scanstop = par.m_totrows;       // randomly close scans
   unsigned sel = urandom(10);
   if (sel < 2) {
     CHK(pkdelete(par) == 0);