/**
* This Locator is to handle Hot Peer load protection, when the Servers are
- * 1) Static
- * 2) Well known client URL
+ * 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.
* @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;
+ 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;
+ /**
+ * 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 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;
+ double d = GreatCircle.calc(info[1],info[2],localLatitude,localLongitude);
+ distances[i]=d;
- // find preferred server
- if(d<distance) {
- preferred = i;
- distance=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]);
- }
- }
- }
+ 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 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);
+ 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;
- }
- }
- }
- }
- }
+ @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 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");
- }
+ if(best<0) {
+ throw new LocatorException("No Clients available");
+ }
- return new HPItem(best);
- }
- }
+ 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;
- }
+ @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";
- }
- }
+ 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 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 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 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 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 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;
- }
- }
- }
+ @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;
+ private static class HPItem implements Item {
+ private int idx;
- public HPItem(int i) {
- idx = i;
- }
- }
+ public HPItem(int i) {
+ idx = i;
+ }
+ }
- /*
- * Convenience Functions
- */
- public CLIENT bestClient() throws LocatorException {
- return get(best());
- }
+ /*
+ * 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;
- }
+ 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;
+ }
}
\ No newline at end of file
Code Review / aaf / authz.git / blobdiff