Fix edge cache behaviour (#3079)

* fixing cache resizing bug

* reenabling test

arangod/Cache/Cache.cpp

@@ -245,7 +245,7 @@ void Cache::requestMigrate(uint32_t requestedLogSize) {
            (requestedLogSize != _table->logSize());
       _metadata.unlock();
       if (ok) {
-        std::tie(ok, _resizeRequestTime) =
+        std::tie(ok, _migrateRequestTime) =
             _manager->requestMigrate(shared_from_this(), requestedLogSize);
       }
     }

arangod/VocBase/Methods/Indexes.cpp

@@ -190,11 +190,19 @@ arangodb::Result Indexes::getAll(arangodb::LogicalCollection const* collection,
         if (val.isNumber()) {
           selectivity += val.getNumber<double>();
         }
+        
+        bool useCache = false;
         VPackSlice figures = index.get("figures");
         if (figures.isObject() && !figures.isEmptyObject()) {
+          if ((val = figures.get("cacheInUse")).isBool()) {
+            useCache = val.getBool();
+          }
           if ((val = figures.get("memory")).isNumber()) {
             memory += val.getNumber<double>();
           }
+          if ((val = figures.get("cacheSize")).isNumber()) {
+            cacheSize += val.getNumber<double>();
+          }
           if ((val = figures.get("cacheLifeTimeHitRate")).isNumber()) {
             cacheLifeTimeHitRate += val.getNumber<double>();
           }
@@ -215,7 +223,7 @@ arangodb::Result Indexes::getAll(arangodb::LogicalCollection const* collection,
           if (withFigures) {
             merge.add("figures", VPackValue(VPackValueType::Object));
             merge.add("memory", VPackValue(memory));
-            if (cacheSize != 0 || cacheLifeTimeHitRate != 0) {
+            if (useCache) {
               merge.add("cacheSize", VPackValue(cacheSize));
               merge.add("cacheLifeTimeHitRate",
                         VPackValue(cacheLifeTimeHitRate / 2));

js/common/tests/shell/shell-collection-rocksdb-noncluster.js

@@ -35,7 +35,6 @@ var testHelper = require("@arangodb/test-helper").Helper;
 var db = arangodb.db;
 var ERRORS = arangodb.errors;
 
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief test suite: collection
 ////////////////////////////////////////////////////////////////////////////////
@@ -405,14 +404,14 @@ function CollectionSuite () {
     },
 
     testEdgeCacheBehaviour : function() {
-      return;
 
       var cn = "UnitLoadBehaviour123";
       db._drop(cn);
       var c = db._createEdgeCollection(cn);
       c.load();
-      for(i=0;i<10000;i++) {
+      for(let i=0;i<10000;i++) {
         c.insert({_from:"c/v"+(i/100), _to:"c/v"+i});
+        c.insert({_to:"c/v"+(i/100), _from:"c/v"+i});
       }
 
       // check if edge cache is present
@@ -422,7 +421,7 @@ function CollectionSuite () {
       var inital = [];
       idxs.forEach(function(idx) {
         if (idx.figures.cacheInUse) {
-          inital.push(idx.figures.cacheSize);
+          inital.push(idx.figures);
         } else {
           inital.push(-1);
         }
@@ -432,23 +431,38 @@ function CollectionSuite () {
 
       // checking if edge cach grew
       idxs = c.getIndexes(true);
-      var i = 0;
+      idxs.forEach(function(idx, i) {
-      idxs.forEach(function(idx) {
         if (idx.figures.cacheInUse) {
-          assertTrue(idx.figures.cacheSize > inital[i], idx);
+          assertTrue(idx.figures.cacheSize > inital[i].cacheSize, idx);
           assertEqual(idx.figures.cacheLifeTimeHitRate, 0, idx);
+          inital[i] = idx.figures;
         }
-        i++;
       });
 
-      for(i=0;i<10000;i++) {
+      for(let i=0;i<10000;i++) {
         c.outEdges("c/v"+(i/100));
+        c.inEdges("c/v"+(i/100));
       }
       idxs = c.getIndexes(true);
-      // cache was filled same queries, hit rate must be bigly
+      // cache was filled same queries, hit rate must be about 
-      idxs.forEach(function(idx) {
+      idxs.forEach(function(idx, i) {
         if (idx.figures.cacheInUse) {
-          assertTrue(idx.figures.cacheLifeTimeHitRate > 0.9, idx);
+          let diff = Math.abs(inital[i].cacheSize - idx.figures.cacheSize);
+          assertTrue(diff <= Math.pow(2, 21), idx);
+          assertTrue(idx.figures.cacheLifeTimeHitRate > 25, idx);
+          inital[i] = idx.figures;
+        }
+      });
+      for(let i=0;i<10000;i++) {
+        c.outEdges("c/v"+(i/100));
+        c.inEdges("c/v"+(i/100));
+      }
+      idxs = c.getIndexes(true);
+      // cache was filled same queries, hit rate must be biglier
+      idxs.forEach(function(idx, i) {
+        if (idx.figures.cacheInUse) {
+          assertTrue(Math.abs(inital[i].cacheSize - idx.figures.cacheSize) < 1024);
+          assertTrue(idx.figures.cacheLifeTimeHitRate > 40, idx);
         }
       });
 
@@ -460,8 +474,9 @@ function CollectionSuite () {
       });
 
       // lets do some reads
-      for(i=0;i<10000;i++) {
+      for(let i=0;i<10000;i++) {
         c.outEdges("c/v"+(i/100));
+        c.inEdges("c/v"+(i/100));        
       }
       idxs = c.getIndexes(true);
       // cache was empty, hit rate should be 0
@@ -472,15 +487,16 @@ function CollectionSuite () {
         }
       });
 
-      for(i=0;i<10000;i++) {
+      for(let i=0;i<10000;i++) {
         c.outEdges("c/v"+(i/100));
+        c.inEdges("c/v"+(i/100));        
       }
       idxs = c.getIndexes(true);
       // cache was partially filled same queries, lifetime hit rate 
       // should be about 50 %
       idxs.forEach(function(idx) {
         if (idx.figures.cacheInUse) {
-          assertTrue(idx.figures.cacheLifeTimeHitRate > 0.45, idx);
+          assertTrue(idx.figures.cacheLifeTimeHitRate > 25, idx);
         }
       });