Java DNS Caching

I have my Java DNS cache expiring every five minutes by setting it up in java.security. My question is - what happens when the DNS server is unreachable, ie. down ? Does Java retain what it already had in the event that it cannot reach a DNS server to update from, or does the domain that was being accessed become unavailable ?

Thank you for your response. At least now I know it isn't something that I misconfigured. It is interesting that if I add this line to obj.conf, the statistics function appears to work, even though according to the admin interface DNS caching is disabled: (I got this from the help system.)
Init cache-size="1024" expire="1200" fn="ip-dns-cache-init"
The original entry put there by the admin interface is:
Init cache-size="1024" expire="1200" negative-dns-cache="yes" fn="host-dns-cache-init"
I do not have a Sun support contract. Is there a procedure to report this bug, or have you already done that?

Similar Messages

HttpURLConnection dns caching

Is there any kind of DNS caching in java.net.HttpURLConnection ?

phiras wrote:
Is there any kind of DNS caching in java.net.HttpURLConnection ?The JVM has settings for DNS caching.
http://mindprod.com/jgloss/dns.html#CACHING

Cache distribution - Java object cache

Hi.
I'm trying to use Oracle Java Object Cache (cache.jar), the one included in the 9iAS 9.0.3.
Everything works fine but the cache distribution between different JVM:s.
Anyone got this to work?
Regards
Jesper
package test;
import oracle.ias.cache.*;
* Singleton Cache class.
public class Cache {
     /** The singleton instance of the object. */
     private static Cache instance = null;
     /** The root region. */
     private final static String APP_NAME = "Test";
     * Protected constructor - Use <code>getInstance()</code>.
     * @throws Exception if error
     protected Cache() throws Exception {
          CacheAccess.defineRegion(APP_NAME);
     * Gets the singleton instance.
     * @return The instance of the Cache object.
     public static Cache getInstance() throws Exception {
          if (instance==null) {
               createInstance();
          return instance;
     * Creates the singleton instance in a thread-safe manner.
     synchronized private static void createInstance() throws Exception {
          if (instance==null) {
               instance = new Cache();
     * Put an object on the cache.
     * @param name The object name
     * @param subRegion The sub region
     * @param object The object to cache
     * @throws Exception if error
     public static void put(String name, String subRegion, Object object) throws Exception {
          CacheAccess appAcc = null;
          CacheAccess subAcc = null;
          try {
               appAcc = CacheAccess.getAccess(APP_NAME);
               // Create a group
               Attributes a = new Attributes();
               a.setFlags(Attributes.DISTRIBUTE);
               appAcc.defineSubRegion(subRegion, a);
               subAcc = appAcc.getSubRegion(subRegion);
               if (!subAcc.isPresent(name)) {
                    subAcc.put(name, a, object);
               } else {
                    subAcc.replace(name, object);
          } catch (CacheException ex){
               // handle exception
               System.out.println(ex.toString());
          } finally {
               if (subAcc != null) {
                    subAcc.close();
               if (appAcc != null) {
                    appAcc.close();
     * Gets a cached object from the specified sub region
     * @param name The object name
     * @param subRegion The sub region
     * @return The cached object
     * @throws Exception if requested object not in cache
     public static Object get(String name, String subRegion) throws Exception {
          CacheAccess appAcc = null;
          CacheAccess subAcc = null;
          Object result = null;
          try {
               appAcc = CacheAccess.getAccess(APP_NAME);
               subAcc = appAcc.getSubRegion(subRegion);
               // define an object and set its attributes
               result = (Object)subAcc.get(name);
          } catch (CacheException ex){
               // handle exception
               throw new Exception("Object '" + name + "' not in cache region '" + subAcc.getRegionName() + "'.");
          } finally {
               if (subAcc != null) {
                    subAcc.close();
               if (appAcc != null) {
                    appAcc.close();
          return result;
     * Invalidates all objects in all regions
     public static void invalidateAll() throws Exception {
          CacheAccess appAcc = CacheAccess.getAccess(APP_NAME);
          appAcc.invalidate(); // invalidate all objects
          appAcc.close(); // close the CacheAccess access
     // Main method for testing purposes.
     public static void main(String[] args) throws Exception {
          try {
               System.out.println(">> Caching object OBJ1 into region TEST1.");
               Cache.getInstance().put("OBJ1", "TEST1", "Object cached in TEST1.");
               System.out.println(">> Getting OBJ1 from cache region TEST1.");
               System.out.println(Cache.getInstance().get("OBJ1", "TEST1"));
          } catch (Exception ex) {
               System.out.println(ex.getMessage());
Contents of JAVACACHE.PROPERTIES:
# discoveryAddress is a list of cache servers and ports
discoveryAddress = host1.myserver.com:12345,host2.myserver.com:12345
logFileName = c:\javacache.log
logSeverity = DEBUG
distribute = true

I have same problem
Exist some reason?
I'm testing Cache with isDistributed() method and I still got false!
Thanx

Clear DNS cache

How can I clear the DNS cache?
When I configure my webserver and change the records, I have to wait the time configured in the ttl of the specific record. I know, that I can change the ttl to a lower value, but the default value is 3 hours, so i have to wait until the time's up.
I checked the DNS records with dig (from dnsutils). dig also shows the remaining seconds until the next refresh (dns server request). And here's my question: How can I refresh it manually? (tried a lot from the internet, but nothing helped)
Thank you guys!
Last edited by gummiflummi (2014-12-16 20:41:53)

brebs wrote:Woah right there. Why do you need to *change* the records? Shouldn't happen often.
Other than the answer stated (to test DNS settings), you might want to change records for a (self-hosted) DynDNS service. If you want a device to updated its DNS entries while being connected to a shaky cellular network, those changes might occur frequently with changing IPs.
To the original poster: You should always set the TTL to a reasonable setting. If you didn't change the record for the last two years, then maybe a TTL of several hours (or even a day) might be OK. If you want to be able to react more quickly to emergency situations, set it lower. For a DynDNS service, TTLs below a minute might be appropriate.
If you want to test your DNS Server, you can always query it directly (bypassing your ISP's DNS servers) with a command like this (where 1.2.3.4 is the IP of your nameserver):
dig @1.2.3.4 your.entry.example.com
This will usually show you the new settings right after changing.

Oracle Application Server 10g Java Object Cache

Hi,
I am new to Java and looking for a java caching framework and just came across Oracle Application Server 10g Java Object Cache. I am unable to find 11g version of the same. Is it not supported any more?
Can I use this with weblogic server? Please suggest if any other alternatives.
Thanks,
Manoj

Bump.
I definitely don't see the same file: C:\dev\jdevstudio10134\javacache\lib\cache.jar in the Oracle JDEV tree. Is there a suggested alternative?

Possible DNS caching problem

I just upgraded to Lion. I am a web deveoper and I just changed the DNS settings for a new website. While everyone else in my office is seeing the new wesite at the domain, I am stuck seeing the old. I have tried the DNS cache flushing techniques below (in addition to restarting, clearing cache, etc), but none have helped:
sudo killall -HUP mDNSResponder
dscachutil -flushcache
In the terminal 'host domain.com' still points to the old server too.
Seems like OSX is holding on to the old DNS settings. Any ideas?

Select  ▹ System Preferences ▹ Network ▹ Advanced ▹ Proxies. If any boxes are checked, uncheck them, apply your changes, and try again. You must apply the changes before they take effect.

How to Flush DNS Cache in Mavericks 10.9.3

So I have seen references to the following when searching for a cmd to flush DNS
sudo killall -HUP mDNSResponder and sudo dscacheutil -flushcache
Which one is proper for Mavericks 10.9.3?

Mountain Lion, but should be applicable to Mavericks.
DNS cache - Reset

Java Object Cache have wired behaviour

HI,
I am trying to get my Oracle Java Object Cache working but I am observing some really stange behaviour which has stop it working. So any help will be really useful (10.1.3 and 10.1.2.0.2). I will explain:
Progammaticly I have setup a parent region call 'DatabaseDataCache' and a sub-region call 'country'. In this region I have defined my object call countriesDto' with a Attribuite that has a CaheLoader attached. In my cache loader I connects to a Entity EJB that loads a bunch of DTOs into the cache.
What is strange is that when i run the unit test on the code (cactus). The cache seems to call the cache loader 3 times consequtively before the EJB will load the data (i know this due to debuging messages)
Then in the actual implmentation I have the cache setup code of the in the init() of the servlet but again the cache loader doesn't seem to able to call the ejb it requires. Ones the cache is access it trys to call the cache loader and of course the ejb dosn't get called and is returning me a NullPointerError as I am trying to acces the local interface (in the cache loader). This is strange as in the cactus test it actually calls the ejb ok bit only on the third attemp.
I am abit puzzled with this so any help will be much appreciated.
Charlie

I think I have got what you need. The following is the cactus test class that test the getCountries method in my session ejb:
public class WebinUtilTest extends ServletTestCase {
private CacheAccess globParCache;
public void setUp() throws Exception {
CacheAccess.defineRegion("DatabaseDataCache");
globParCache = CacheAccess.getAccess("DatabaseDataCache");
globParCache.defineSubRegion("country");
Attributes cAtt = new Attributes();
cAtt.setLoader(new CountryCacheLoader());
CacheAccess globCountCache = globParCache.getSubRegion("country");
globCountCache.defineObject("countriesDto", cAtt);
globCountCache.preLoad("countriesDto");
globCountCache.close();
globParCache.close();
public void testGetCountries() throws Exception{
WebinUtilLocal wuLoc = HomeFactory.getWebinUtilLocalHome().create();
String[] countries = wuLoc.getCountries();
assertTrue(countries.length >0);
public void tearDown() throws Exception {
if (globParCache != null){
CacheAccess gCache = CacheAccess.getAccess("DatabaseDataCache");
gCache.destroy();
When I run this test here is the stack trace I am getting (in order):
06/01/05 15:54:14 load entred for country cache loader: Thu Jan 05 15:54:14 GMT 2006
06/01/05 15:54:14 java.lang.Exception: Stack trace
06/01/05 15:54:14 at java.lang.Thread.dumpStack(Thread.java:1064)
06/01/05 15:54:14 at uk.ac.ebi.submission.util.CountryCacheLoader.load(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheLoader.callLoad(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.findObject(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.asyncLoad(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.Task.execute(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.WorkerThread.run(Unknown Source)
06/01/05 15:54:14 WebinUtil Session Started: Thu Jan 05 15:54:14 GMT 2006
06/01/05 15:54:14 load entred for country cache loader Thu Jan 05 15:54:14 GMT 2006
06/01/05 15:54:14 java.lang.Exception: Stack trace
06/01/05 15:54:14 at java.lang.Thread.dumpStack(Thread.java:1064)
06/01/05 15:54:14 at uk.ac.ebi.submission.util.CountryCacheLoader.load(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheLoader.callLoad(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.findObject(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.locateObject(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheAccess.get(Unknown Source)
06/01/05 15:54:14 at uk.ac.ebi.submission.ejb.session.WebinUtilBean.getCountries(Unknown Source)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
06/01/05 15:54:14 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
06/01/05 15:54:14 at java.lang.reflect.Method.invoke(Method.java:324)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.EJBJoinPointImpl.invoke(EJBJoinPointImpl.java:39)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:45)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:62)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.JAASInterceptor$1.run(JAASInterceptor.java:32)
06/01/05 15:54:14 at java.security.AccessController.doPrivileged(Native Method)
06/01/05 15:54:14 at javax.security.auth.Subject.doAs(Subject.java:379)
06/01/05 15:54:14 at com.evermind.server.ThreadState.runAs(ThreadState.java:637)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.JAASInterceptor.invoke(JAASInterceptor.java:36)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.TxRequiredInterceptor.invoke(TxRequiredInterceptor.java:56)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.SecurityRoleInterceptor.invoke(SecurityRoleInterceptor.java:46)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:62)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.RunningStateInterceptor.invoke(RunningStateInterceptor.java:28)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.StatelessSessionEJBObject.OC4J_invokeMethod(StatelessSessionEJBObject.java:106)
06/01/05 15:54:14 at WebinUtilLocal_StatelessSessionBeanWrapper50.getCountries(WebinUtilLocal_StatelessSessionBeanWrapper50.java: 310)
06/01/05 15:54:14 at uk.ac.ebi.submission.cactus.session.WebinUtilTest.testGetCountries(Unknown Source)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
06/01/05 15:54:14 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
06/01/05 15:54:14 at java.lang.reflect.Method.invoke(Method.java:324)
06/01/05 15:54:14 at junit.framework.TestCase.runTest(TestCase.java:154)
06/01/05 15:54:14 at junit.framework.TestCase.runBare(TestCase.java:127)
06/01/05 15:54:14 at org.apache.cactus.internal.AbstractCactusTestCase.runBareServer(AbstractCactusTestCase.java:153)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestCaller.doTest(AbstractWebTestCaller.java:119)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestController.handleRequest_aroundBody0(AbstractWebTestControl ler.java:93)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestController.handleRequest_aroundBody1$advice(AbstractWebTest Controller.java:224)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestController.handleRequest(AbstractWebTestController.java)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doPost_aroundBody2(ServletTestRedirector.java:101)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doPost_aroundBody3$advice(ServletTestRedirector.java:224)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doPost(ServletTestRedirector.java)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doGet_aroundBody0(ServletTestRedirector.java:72)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doGet_aroundBody1$advice(ServletTestRedirector.java:224)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doGet(ServletTestRedirector.java)
06/01/05 15:54:14 at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
06/01/05 15:54:14 at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
06/01/05 15:54:14 at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:64)
06/01/05 15:54:14 at oracle.security.jazn.oc4j.JAZNFilter.doFilter(JAZNFilter.java:382)
06/01/05 15:54:14 at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:701)
06/01/05 15:54:14 at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:397)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:833)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:430)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler.java:216)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:119)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:215)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:232)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketAcceptHandler.access$1000(ServerSocketAcceptHandler.java:35)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:819)
06/01/05 15:54:14 at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303)
06/01/05 15:54:14 at java.lang.Thread.run(Thread.java:534)
Hope this is enough information.
Thanks
Charlie

Flushing the DNS cache

I'm having trouble with a Web site when I access it on my home computer, yet this same site looks fine on my Mini at work. One section of the index page generates a "can't find server" error, and the site's own logo won't display properly. It is a free hosting site. Sometimes I can upload files to it, other times I get a can't-find-server error when I try.
In answer to my query about this (to which I helpfully attached a screenshot of the incompletely loaded index page and its error messages), the host is telling me that I should "flush my DNS cache," which they say involves going into Terminal and giving the command "ookupd -flushcache" [sic]. (I've already surfed this briefly and the first result confirmed my suspicion that this doofus hasn't mastered copy-and-paste technique and the command actually should be "lookupd- flushcache".)
It's not just that their site doesn't load fully, though. They have some stuff on one of their pages that they encourage users to hotlink on personal Web sites, and I have done that with one of their banners. The banner, which was fine for months, now appears on my page as a broken icon, too, although it, like the site's home page, loads fine on my computer at work.
My first question is, is there any harm in flushing the DNS cache? The OS Daily page where I think they copied this advice from makes it sound like this is something only a Web server would need. If I do it on my home machine, could it cause problems? Could it disable my Internet connectivity?
Second, less urgent question, more for the netgeeks out there: Do you think this is a likely solution to my problem? Especially considering that the problem involves not only their site but an element on an external site linking back to them? I hate to play the sucker for some low-level geek whose main mission is to deflect my query.
Thanks
Kathi

Kathi--
Like BDAqua says, there's nothing to worry about flushing the DNS cache. It's true that most people probably don't need to do it very often, but it's something easy and harmless to try, and it might well fix problems like yours.
One handy feature of Safari, even if you don't use it for anything else, is the "Activity" window. Open it from the "View" menu, and watch as your page loads. You can see exactly which components on the page are loading, which aren't and where they should be coming from. If you double-click an element in that list, Safari will try to open it in a new window. That is sometimes enough to give a clue as to why something isn't working.
You can use Safari's activity list along with the Network Utility from your Utilities folder to try to figure out why you're not getting the page elements. Suppose a graphic is listed as coming from http://www.server1.com/images/logo.jpg, but it's not loading.
First thing I would try in the Network Utility is to see if it will respond to pings. From that example, enter "www.server1.com" on the "Ping" page of the Network Utility and see if it answers back.
To find out if it's a DNS problem, you can use Safari's list to get the addresses of the problem elements, then see if the IP addresses match up on your computer at home to the one at work. If they don't, then it could be stale DNS.
You can use the Network Utility for DNS lookups, but I think they're hard to read, and, since you're already thinking about using the Terminal to flush the DNS cache, you can use nslookup. It's really simple:
<pre class="command">nslookup www.apple.com</pre>
Will give you something like this (the first two lines will likely be different):
Server: 208.67.222.222
Address: 208.67.222.222#53
Non-authoritative answer:
www.apple.com canonical name = www.apple.com.akadns.net.
Name: www.apple.com.akadns.net
Address: 17.251.200.32
If the addresses don't match, or you get a message that it can't find anything for your server, then you know it's a DNS problem. Perhaps they've changed some addresses and your home ISP's DNS servers themselves aren't updating.
You can even use nslookup to see what different DNS servers say about an address. Just add the IP address of a DNS server after the address you want to look up:
<pre class="command">nslookup www.apple.com 208.67.220.220</pre>
Just do a search on the 'net for free DNS servers, and you'll find a bunch to choose from.
charlie

My Upgrading Java Applets Cache won't finish

I had to reinstall Java 6.0 and each time I try to run something requiring Java, it doesn't load. All I get is a box stating Upgrading Java Applets Chache, it runs about half way and then quits. I am getting very frustrated after working on this for 2 days.
It says "Please wait while your stored Java Applets are updated for Java SE 6". Runs for about 20 secs and then stops and the box disappears. Does anybody have any suggestions? I am not very computer savvy so please explain in simple terms.
Thanks

Hi
I had the exact same problem. took me days to find the solution, hope it works for you.
Click on the START button bottom left on the screen, Then look for the CONTROL PANEL button and click, (this should bring up lots of icons for programmes) on some computers its under themes and sttings I think. Click on the JAVA icon this brings up a CONTROL PANEL. Click on SETTINGS at the bottom, then click DELETE FILES. (this took a while to complete on my computer) Just to make sure after you've done this bring up the JAVA CONTROL PANEL again but this time click on ADVANCED. Then at the bottom theres is Miscellaneous, click on this and there should be JAVA QUICK STARTER with a box ticked next to it, Click on the tick and get rid of it then click on OK..
Try a website that uses Java. the cache box might appear again but just hit cancel. When I tried this i was able to use Java again.
Hope it works

How can I clear the DNS cache?

I haven't been able to connect to my local Library since January. When I key in the URL, it starts the access routine and then after about 20 minutes, I have to kill it because nothing happens. I contacted the IT folks at the library and was told that they had made a few changes around the time my problem began so maybe the DNS cache was still pointing at the old info. He recommended that I enter TERMINAL mode and try to clear the DNS cache, using "sudo dscacheutil -flushcache" command. . I attempted this several times, even changing my applid password, and kept getting invalid responses.

I did try that and after a few trys it finally worked. It took quite awhile for the window for the library to finally come up, but it did and I am now able to get in and out with no problems with my library access. Now when I call up my bank, parts of it don't come up and it kicks me out. Now, I'll have to search for what fixes that - as it has happened before, so I know it's fixable. Thanks for you help though.

Export DNS cache

After searching around, I've found a ton of posts about clearing DNS Cache, but what I'm actually looking for is a way to export the DNS cache out of bind to some sort of text file. Basically, I'm hoping to build a static dns cache lookup file to use with AWStats, and wanted to see if it was worthwhile using entries from the several DNS servers we having running.

Hi Alex
rndc dumpdb should do.
Regards
--greg

Flush the DNS cache

How do i flush the DNS cache on an iPhone?

TrYaN73 wrote:
How do i flush the DNS cache on an iPhone?
There's no specific way to do that exact thing in iOS. However, resetting network settings will help resolve a lot of network-related issues for both Wi-Fi and cellular connections.
Reset network settings by tapping Settings > General > Reset > Reset Network Settings.

DNS Caching

I am having some trouble understanding the operation and configuration of DNS caching on a CE.
Does the listener command intercept the CE's DNS requests that would normally go to the nameserver configured with the "ip name-server" command(s) and send them to the name or address used in the listener command?
What does this mean: " The DNS server must know the DNS name of the host on which it is being enabled and map it to an IP address within its own cache."? I can't tell if the DNS server referenced is the CE.
Also, is it more common to limit the cache size on the smaller end of the scale or the upper end?
Thanks.

"dns listen" command has to be configured with the name and ip address of your dns server. You can use the "dns pin" command to do this.
http://www.cisco.com/univercd/cc/td/doc/product/webscale/uce/acns50/cref50/14623ref.htm#2408858
DNS-caching on the CE is not a "caching dns server". It is only for the CE to use itself - and not to point the PC's "dns server" at. DNS is only needed in Proxy mode.

HT5343 Resetting the DNS cache does not seem to work on OS X 10.8, what does really work?

Resetting the DNS cache does not seem to work on OS X 10.8, what does really work?
Desired activity: access a site that used to not have a SSL connection through the new https:// root domain. I can accomplish the task over a machine running Windows 7 or XP but flushing the dns of my mac does not affect the outcome — I am still redirected to the hosting provider's website whenever I tried to access the domain with a https:// prefix rather than http://
I tried sudo killall -HUP mDNSResponder and it's older alternative but no luck.

In the terminal:
dscacheutil -flushcache
and to get a very detailed report on the state of your DNS cache in /var/logs/system.log:
sudo killall -INFO mDNSResponder

Java DNS Caching

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