Add method getNextFlowEntryId() which is used internally to generate
the FlowEntryIDs. Currently, for simplicity the upper 32 bits are
randomly generated, while the lower 32 bits are sequential.
If all lower 32 bits are used, the upper 32 bits are regenerated.
In the future, we should use a better mechanism (e.g., use
Zookeeper to generate the upper 32 bits in semi-sequential fashion,
and to guarantee they are unique).
diff --git a/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java b/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java
index 38f4220..6036678 100644
--- a/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java
+++ b/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java
@@ -3,14 +3,15 @@
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
+import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
+import java.util.Random;
import java.util.TreeMap;
-import java.util.Collections;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
@@ -87,7 +88,12 @@
public static final short FLOWMOD_DEFAULT_HARD_TIMEOUT = 0; // infinite
public static final short PRIORITY_DEFAULT = 100;
- private static long nextFlowEntryId = 1;
+ // Flow Entry ID generation state
+ private static Random randomGenerator = new Random();
+ private static int nextFlowEntryIdPrefix = 0;
+ private static int nextFlowEntryIdSuffix = 0;
+ private static long nextFlowEntryId = 0;
+
private static long measurementFlowId = 100000;
private static String measurementFlowIdStr = "0x186a0"; // 100000
private long modifiedMeasurementFlowTime = 0;
@@ -644,22 +650,30 @@
this.init(conf);
}
+ private long getNextFlowEntryId() {
+ //
+ // Generate the next Flow Entry ID.
+ // NOTE: For now, the higher 32 bits are random, and
+ // the lower 32 bits are sequential.
+ // In the future, we need a better allocation mechanism.
+ //
+ if ((nextFlowEntryIdSuffix & 0xffffffffL) == 0xffffffffL) {
+ nextFlowEntryIdPrefix = randomGenerator.nextInt();
+ nextFlowEntryIdSuffix = 0;
+ } else {
+ nextFlowEntryIdSuffix++;
+ }
+ long result = (long)nextFlowEntryIdPrefix << 32;
+ result = result | (0xffffffffL & nextFlowEntryIdSuffix);
+ return result;
+ }
+
@Override
public void startUp(FloodlightModuleContext context) {
restApi.addRestletRoutable(new FlowWebRoutable());
- //
- // Extract all flow entries and assign the next Flow Entry ID
- // to be larger than the largest Flow Entry ID
- //
- Iterable<IFlowEntry> allFlowEntries = conn.utils().getAllFlowEntries(conn);
- for (IFlowEntry flowEntryObj : allFlowEntries) {
- FlowEntryId flowEntryId =
- new FlowEntryId(flowEntryObj.getFlowEntryId());
- if (flowEntryId.value() >= nextFlowEntryId)
- nextFlowEntryId = flowEntryId.value() + 1;
- }
- conn.endTx(Transaction.COMMIT);
+ // Initialize the Flow Entry ID generator
+ nextFlowEntryIdPrefix = randomGenerator.nextInt();
}
/**
@@ -687,7 +701,7 @@
// TODO: This needs to be redesigned!
//
for (FlowEntry flowEntry : flowPath.dataPath().flowEntries()) {
- long id = nextFlowEntryId++;
+ long id = getNextFlowEntryId();
flowEntry.setFlowEntryId(new FlowEntryId(id));
}