diff options
Diffstat (limited to 'client/src/main/java/org/onap/aaf/cadi/locator/HotPeerLocator.java')
| -rw-r--r-- | client/src/main/java/org/onap/aaf/cadi/locator/HotPeerLocator.java | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/client/src/main/java/org/onap/aaf/cadi/locator/HotPeerLocator.java b/client/src/main/java/org/onap/aaf/cadi/locator/HotPeerLocator.java new file mode 100644 index 0000000..04d2a28 --- /dev/null +++ b/client/src/main/java/org/onap/aaf/cadi/locator/HotPeerLocator.java @@ -0,0 +1,304 @@ +/*******************************************************************************
+ * ============LICENSE_START====================================================
+ * * org.onap.aaf
+ * * ===========================================================================
+ * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
+ * * ===========================================================================
+ * * Licensed under the Apache License, Version 2.0 (the "License");
+ * * you may not use this file except in compliance with the License.
+ * * You may obtain a copy of the License at
+ * *
+ * * http://www.apache.org/licenses/LICENSE-2.0
+ * *
+ * * Unless required by applicable law or agreed to in writing, software
+ * * distributed under the License is distributed on an "AS IS" BASIS,
+ * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * * See the License for the specific language governing permissions and
+ * * limitations under the License.
+ * * ============LICENSE_END====================================================
+ * *
+ * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
+ * *
+ ******************************************************************************/
+package org.onap.aaf.cadi.locator;
+
+import org.onap.aaf.cadi.Access;
+import org.onap.aaf.cadi.Locator;
+import org.onap.aaf.cadi.LocatorException;
+import org.onap.aaf.cadi.Access.Level;
+import org.onap.aaf.cadi.routing.GreatCircle;
+
+import org.onap.aaf.inno.env.util.Split;
+
+/**
+ * This Locator is to handle Hot Peer load protection, when the Servers are
+ * 1) Static
+ * 2) Well known client URL
+ *
+ * The intention is to change traffic over to the Hot Peer, if a server goes down, and reinstate
+ * when it is back up.
+ *
+ * Example of this kind of Service is a MS Certificate Server
+ *
+ *
+ *
+ * @param <CLIENT>
+ */
+public abstract class HotPeerLocator<CLIENT> implements Locator<CLIENT> {
+ private final String[] urlstrs;
+ private final CLIENT[] clients;
+ private final long[] failures;
+ private final double[] distances;
+ private int preferred;
+ private long invalidateTime;
+ private Thread refreshThread;
+ protected Access access;
+
+ /**
+ * Construct: Expect one or more Strings in the form:
+ * 192.555.112.223:39/38.88087/-77.30122
+ * separated by commas
+ *
+ * @param trans
+ * @param urlstr
+ * @param invalidateTime
+ * @param localLatitude
+ * @param localLongitude
+ * @throws LocatorException
+ */
+ @SuppressWarnings("unchecked")
+ protected HotPeerLocator(Access access, final String urlstr, final long invalidateTime, final String localLatitude, final String localLongitude) throws LocatorException {
+ this.access = access;
+ urlstrs = Split.split(',', urlstr);
+ clients = (CLIENT[])new Object[urlstrs.length];
+ failures = new long[urlstrs.length];
+ distances= new double[urlstrs.length];
+ this.invalidateTime = invalidateTime;
+
+ double distance = Double.MAX_VALUE;
+ for(int i=0;i<urlstrs.length;++i) {
+ String[] info = Split.split('/', urlstrs[i]);
+ if(info.length<3) {
+ throw new LocatorException("Configuration needs LAT and LONG, i.e. ip:port/lat/long");
+ }
+ try {
+ clients[i] = _newClient(urlstrs[i]);
+ failures[i] = 0L;
+ } catch(LocatorException le) {
+ failures[i] = System.currentTimeMillis()+invalidateTime;
+ }
+
+ double d = GreatCircle.calc(info[1],info[2],localLatitude,localLongitude);
+ distances[i]=d;
+
+ // find preferred server
+ if(d<distance) {
+ preferred = i;
+ distance=d;
+ }
+ }
+
+ access.printf(Level.INIT,"Preferred Client is %s",urlstrs[preferred]);
+ for(int i=0;i<urlstrs.length;++i) {
+ if(i!=preferred) {
+ access.printf(Level.INIT,"Alternate Client is %s",urlstrs[i]);
+ }
+ }
+ }
+
+ protected abstract CLIENT _newClient(String hostInfo) throws LocatorException;
+ /**
+ * If client can reconnect, then return. Otherwise, destroy and return null;
+ * @param client
+ * @return
+ * @throws LocatorException
+ */
+ protected abstract CLIENT _invalidate(CLIENT client);
+
+ protected abstract void _destroy(CLIENT client);
+
+ @Override
+ public Item best() throws LocatorException {
+ if(failures[preferred]==0L) {
+ return new HPItem(preferred);
+ } else {
+ long now = System.currentTimeMillis();
+ double d = Double.MAX_VALUE;
+ int best = -1;
+ boolean tickle = false;
+ // try for best existing client
+ for(int i=0;i<urlstrs.length;++i) {
+ if(failures[i]<now && distances[i]<d) {
+ if(clients[i]!=null) {
+ best = i;
+ break;
+ } else {
+ tickle = true; // There's some failed clients which can be restored
+ }
+ }
+ }
+ if(best<0 && tickle) {
+ tickle=false;
+ if(refresh()) {
+ // try again
+ for(int i=0;i<urlstrs.length;++i) {
+ if(failures[i]==0L && distances[i]<d) {
+ if(clients[i]!=null) {
+ best = i;
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ /*
+ * If a valid client is available, but there are some that can refresh, return the client immediately
+ * but start a Thread to do the background Client setup.
+ */
+ if(tickle) {
+ synchronized(clients) {
+ if(refreshThread==null) {
+ refreshThread = new Thread(new Runnable(){
+ @Override
+ public void run() {
+ refresh();
+ refreshThread = null;
+ }
+ });
+ refreshThread.setDaemon(true);
+ refreshThread.start();
+ }
+ }
+ }
+
+ if(best<0) {
+ throw new LocatorException("No Clients available");
+ }
+
+
+ return new HPItem(best);
+ }
+ }
+
+
+ @Override
+ public CLIENT get(Item item) throws LocatorException {
+ HPItem hpi = (HPItem)item;
+ CLIENT c = clients[hpi.idx];
+ if(c==null) {
+ if(failures[hpi.idx]>System.currentTimeMillis()) {
+ throw new LocatorException("Client requested is invalid");
+ } else {
+ synchronized(clients) {
+ c = _newClient(urlstrs[hpi.idx]);
+ failures[hpi.idx]=0L;
+ }
+ }
+ } else if(failures[hpi.idx]>0){
+ throw new LocatorException("Client requested is invalid");
+ }
+ return c;
+ }
+
+ public String info(Item item) {
+ HPItem hpi = (HPItem)item;
+ if(hpi!=null && hpi.idx<urlstrs.length) {
+ return urlstrs[hpi.idx];
+ } else {
+ return "Invalid Item";
+ }
+ }
+
+ @Override
+ public boolean hasItems() {
+ for(int i=0;i<clients.length;++i) {
+ if(clients[i]!=null && failures[i]==0L) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ @Override
+ public synchronized void invalidate(Item item) throws LocatorException {
+ HPItem hpi = (HPItem)item;
+ failures[hpi.idx] = System.currentTimeMillis() + invalidateTime;
+ CLIENT c = clients[hpi.idx];
+ clients[hpi.idx] = _invalidate(c);
+ }
+
+ @Override
+ public Item first() throws LocatorException {
+ return new HPItem(0);
+ }
+
+ @Override
+ public Item next(Item item) throws LocatorException {
+ HPItem hpi = (HPItem)item;
+ if(++hpi.idx>=clients.length) {
+ return null;
+ }
+ return hpi;
+ }
+
+ @Override
+ public boolean refresh() {
+ boolean force = !hasItems(); // If no Items at all, reset
+ boolean rv = true;
+ long now = System.currentTimeMillis();
+ for(int i=0;i<clients.length;++i) {
+ if(failures[i]>0L && (failures[i]<now || force)) { // retry
+ try {
+ synchronized(clients) {
+ if(clients[i]==null) {
+ clients[i]=_newClient(urlstrs[i]);
+ }
+ failures[i]=0L;
+ }
+ } catch (LocatorException e) {
+ failures[i]=now+invalidateTime;
+ rv = false;
+ }
+ }
+ }
+ return rv;
+ }
+
+ @Override
+ public void destroy() {
+ for(int i=0;i<clients.length;++i) {
+ if(clients[i]!=null) {
+ _destroy(clients[i]);
+ clients[i] = null;
+ }
+ }
+ }
+
+ private static class HPItem implements Item {
+ private int idx;
+
+ public HPItem(int i) {
+ idx = i;
+ }
+ }
+
+
+ /*
+ * Convenience Functions
+ */
+ public CLIENT bestClient() throws LocatorException {
+ return get(best());
+ }
+
+ public boolean invalidate(CLIENT client) throws LocatorException {
+ for(int i=0;i<clients.length;++i) {
+ if(clients[i]==client) { // yes, "==" is appropriate here.. Comparing Java Object Reference
+ invalidate(new HPItem(i));
+ return true;
+ }
+ }
+ return false;
+ }
+
+ }
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