Refreshing cached DNS directory

So it looks like when a DNS zone is listed (using a DirContext.listBindings() method) it is cached so that subsequent calls to listBindings will not cause another zone transfer.
However, in my case I would like to force another DNS zone transfer. I've tried closing the context. I've tried creating a brand new context (using InitialDirContext()) to no avail.
Is there a way to force this DNS zone transfer upon demand?

I'm working around this limitation by setting a very short TTL in the DNS records. This is just a guess, but I think the DirContext is trying to be smart about when it should initiate another zone transfer based on the TTL.

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How to set up with cacheing DNS for local network?

Our new Lion Server has a static IP Address pointed to over the internet by our registrar's zone file. Planning the Lion Server installation process with the intent of hosting Web, Mail and Open Directory services to a small number of users who are nearly all located off-site. I do also want Lion Server to be a caching DNS Server and DHCP authority on the local network to replace what dnsmasq does on our current Linux server.
I am looking forward to offloading some of the lower level Linux administration tasks and putting myself in the hands of the Lion Server Setup Assistant and Server App :-) but at the same time don't understand some of its assumptions and fear having to spend a lot of time experimenting and re-installing.
So, specifically, I want the Server App to know that my Lion Server has a "Host Name for the Internet" but that the DNS it sets up will not be the DNS for my zone - I will be managing that through my registrar's interfaces.
Second problem is my fnot understanding what name space devices on the local network will / should use. e.g. The Linux server will be available for backups etc on the local intranet (and optionally have a static ip address on the Internet) but MacBooks, PCs, iPads and iPhones will be served ip addresses by the Lion Server's DHCP. So will / should these dynamic devices have their machine names fully qualified by our domain name with RFC 1918 style ip addresses or something like .local? How do I tell this to Lion's Server App / Setup Assistant? How easy is it to update these initial settings later?

You do indeed need to have a master zone on lion server. There's no way to get around that since Open Directory depends on Kerberos and Kerberos depends on the DNS. LS scripts may see that the rDNS record exists, but I highly doubt that it'll auto configure everything for you... and given the number of possible variables, I bet that even if it worked something would need additional tweaking.
Sounds like an interesting lab excersize. You should try it on a test server!
Again... you just need to folow the set up procedure that Lion Server presents you with.
It won't be smart enough to see your external records and use them to configure a key distribution center for your OD.
As far as your caching needs... Could you set up your DHCP server to set the DNS server setting to show your internal server as the first hit, and your external as the second? That way when the client requests a resolution it'll not get a hit on your local server but will from the external?
The question then is how long will it wait for a response from the first server? Or will the first server respond with "I don't know" sending the client immediately to the second.
The server set up that I have works similarly. I have an internal master DNS that is replicated to a secondary. The first DNS has an A record (community.server.com) that points to the INTERNAL ip address of the secondary server that's also running the web service. The first server is running DHCP. It tells the clients to use the first and second servers as it's DNS lookup.
Now... Externally, my registrar hosts an A record for community.server.com that points to the external IP address of my router which then forwards the request to the proper port on the internal network.
This way, the local clients internally look up and get a response locally when they go for community.server.com. Externally, clients that look up community.server.com get the external connection to the router in my school.
Yikes... I fear that this is as clear as mud!
-Graham

Catche Notification in Catche Overview - while refreshing Cache

Hi All facing foolowing error while refreshing cache,
"Unable to determine the name of Central Adapter engine from the System landscape directory at this time. Notification to Central adapter engine are therefore listed using the technical name of adapter engine. This is usually structured as follows: af:<SAP System ID>.<Name of Application Sever>
Please help.
Regards,
Nitin

Hi
Log in into XI and run the transaction SLDCHECK and see whether you have success or any errors?
Check this Blog. it should probabaly solve your problem.
Adapter Engine cannot be found in Integration Directory

Unable to refresh cache in XI - UPdate error - HTTP 404

Hi All,
When we try to refresh cache we get the error HTTP 404. All the RFC Destinations like HMI DIrectory, XI DIRECTORY, XIRUNTIME all are showing the same error - HTTP 404.
We tried to refersh cache fully from /rep -> Administration for INtegration server and Integration Directory.
It tries to access http://hostname:8000/sap/xi/cache?sap-client=001&mode=F and pops up user credentails. It does not accept any user I give. I have tried PISUPER and J2EE_ADMIN with all authorization for PI. STil it keep asking for user id again and again. It does not go in at all.
The SLD Cache is refreshed successfuly.
Please let me know the steps for troubleshooting this issue.
Thanks and Regards,
Raghavan

Hi Raghavan,
for the SM59 destination the user should be XIISUSER or PIISUSER (depending on your release).
Check that the user isn't locked (TCODE SU01)
Also check
(1)
(TCODE SICF )that
"default_host->sap->xi->cache/engine" has been activated.
(2)
the application
sap.com/com.sap.xi.directory
is started
i.e.,
from NWA
[start_stop_applications |http://wiki.sdn.sap.com/wiki/x/BQH5Bg ]
or
VA
service
-> Deploy
-> Applictaions TAB
(3)
SM59
destination - INTEGRATION_DIRECTORY_HMI
recheck that the correct port and client are specified and that the user is XIISUER/PIISUER
Regards
Kenny

Error during last attempt to refresh cache in tranaction sxi_cache

Dear Team,
We are geting below error , while executing sxi_cache transaction . please suggest .
Status of Runtime Cache.
Cache content is up-to-date
Error during last attempt to refresh cache , wile double clicking this , we found below log .
Thrown:
com.sap.aii.ib.server.abapcache.CacheRefreshException: Attempt to access application REPOSITORY using HTTP Method Invocation (HMI) failed. Detailed information: Invoking ROA method "ReadObjects" via HMI ... FAILED due to following exception: Message: Connection to system REPOSITORY using application REPOSITORY lost. Detailed information: Error accessing "http://gsapnppid.galsap.local:50000/rep/remoteobjectaccess/int?container=ejb" with user "PIDIRUSER". Response code is 401, response message is "Unauthorized"
Stacktrace:
com.sap.aii.utilxi.hmi.api.HmiCoreException: Connection to system REPOSITORY using application REPOSITORY lost. Detailed information: Error accessing "http://gsapnppid.galsap.local:50000/rep/remoteobjectaccess/int?container=ejb" with user "PIDIRUSER". Response code is 401, response message is "Unauthorized"
at com.sap.aii.utilxi.hmi.api.HmiCoreException.newCommunicationError(HmiCoreException.java:85)
Kindly Advise

Please Check if the user PIDIRUSER is locked.
If user is not locked, check if the credential for user PIDIRUSER and respective password is correctly maintained in Exchange Profile.
Regards,
Murali Narayanan

Error in Cache Refresh(Unable to refresh cache contents)

Hi All,
When i am refreshing Cache from the browser using link CPACache/refresh?mode=full it says success.
When i do from SXI_CACHE it gives an error.
 Error during last attempt to refresh cache
 Unable to refresh cache contents
So when i run any schenario in message monitoring i get the following error-
SAP:Error xmlns:SAP="http://sap.com/xi/XI/Message/30" xmlns:SOAP="http://schemas.xmlsoap.org/soap/envelope/" SOAP:mustUnderstand="1">
<SAP:Category>XIServer</SAP:Category>
<SAP:Code area="XICACHE">UPDATE</SAP:Code>
<SAP:P1 />
<SAP:P2 />
<SAP:P3 />
<SAP:P4 />
<SAP:AdditionalText>http response does not contain a valid XML root tag</SAP:AdditionalText>
<SAP:ApplicationFaultMessage namespace="" />
<SAP:Stack>An error occurred when refreshing the XI runtime cache</SAP:Stack>
<SAP:Retry>N</SAP:Retry>
</SAP:Error>
I checked the INTEGRATION_DIRECTORY_HMI connection...
here the response which im getting is..
 HEADER NAME HEADER VALUE
response_line HTTP/1.0 200
server_protocol HTTP/1.0
status_code 200
status_reason
ragma no-cache
ache-control no-cache
ontent-type text/html
ontent-length 87
HTTP BODY
TITLE>Error</TITLE>#<BODY>#<H1>Error</H1>#FW-1 at nebula: Unknown WWW s
rver.</BODY>##
Time (ms) 17
I believe that is not the right response.
Everything was working fine yesterday when all of a sudden this error cropped up from no where.
Regards,
Rahul

Hi,
This is the error it shows there..
ERROR ID UPDATE
http response does not contain a valid XML root tag
Regards,
Rahul

Could not albe to refresh cache

If 500 says HTTP connection.
I do not understand why my cache is not getting refreshed.
I am getting an error "Could not able to refresh cache",Error while trying to refresh the cache in sxi_cache.
Please Clarify.
Thanks.
Srini

Did you go through the Document in this thread? Refer to the trouble shooting section and try to debug,
could not able to refresh cache
Regards
Bhavesh

Error while refreshing cache

Hi ,
My scnearo was working fine . Suddenly i am getting this error in moni
error while refreshing cache
if any one ever faced this problem plz let me now
thanks
amit

Hi Amit,
1. Check the RFC destination INTEGRATION_DIRECTORY_HMI in transaction sm59. Check the connection and the username & pwd.
2. Check the HTTP services default_host/sap/xi/cache and default_host/sap/xi/cache_ssl. They should be active.
There are other troubleshooting steps outlined in the document 'How To Handle Caches in SAP XI 3.0'. I suggest you go through them.
https://websmp104.sap-ag.de/~sapdownload/011000358700003163902004E/HowTo_handle_XI_30_Caches.pdf
Cheers
Manish

GSS (vs) Cached DNS responses

I am trying to understand the GSS product and how it provides 'immediate' redundancy across multiple data center(s).
So lets assume that the GSS (with CNR installed) has been deployed and functions as the authoritative server for the domain (www.test.com). The goal is to provide active/standby type configuration between two data centers.
If a client tries to access the page (www.test.com), the GSS replies with the address of server (e.g: 1.1.1.1) residing in Data Center(a). However lets assume after the response from GSS is sent to client and the client is trying to connect to the www.test.com using Ip address 1.1.1.1, Data Center(a) becomes unavailable. How will this connection get redirected to Data Center(b)'s IP address 2.2.2.2?
All subsequest request from the client will be done using 'DNS cache' so the GSS does not come into the picture since the client already knows the IP address of www.test.com (1.1.1.1).
Is this how it works or am I missing something here?
Thanks in advance for the response.

Syed
There are few things you should keep in mind.
User Workstation is not the real client for GSS. Its primarily the Client's DNS Server.
With respect to caching you are very correct that GSS (for that matter any DNS based GSLB method) is prone to DNS caching issues.
There are various points in the network that stores/caches DNS information.
1. Client's DNS Servers
2. Client PC's OS
3. Browser on Client's PC
To mitigate Client DNS Server issue you need configure the A record served by GSS with a smaller TTL value. This "A-record TTL value" dictates how long can DNS server caches a DNS record. So for example if you set A-record TTL value to 5 minute then the worst outage of service you will get will be 5 minutes (as Client's DNS server will only cache it for 5 minutes and at 6th minute Client's DNS server will contact GSS again and will get the active vip as answer.
If you are using newer IE versions (6.x+) then you are in a better situation as these IEs try to resolve again if the web access to IP in DNS cache fails and hence will get the active IP on GSS.With Pre-6.x versions problem is severe as not only this feature is missing but also the DNS caching time is from 30 mins to 24 hours.
With Firefox (last time I checked) this dns cache timeout is 15 minute (so in worst case scenario the service outage will be 15 minutes).
Using google you can get lots of tools to disable dns caching on browsers. I know this is not a cool solution but it can be done.
In nutshell yes GSLB has issues with DNS caching but it still gives you a solution which can move client to a different Data center (after dns cache timeout).
Syed Iftekhar Ahmed

SXI_CACHE Error: Unable to refresh cache contents

Hello everybody,
in SXI_CACHE we get the error:
"Unable to refresh cache contents"
"Error during last attempt to refresh cache"
and on double clicking we get the message:
Error Id: Communication
if_http_client receive http_communication_failure.
Any suggestions.
We can't afford to restart the machines every time.
Regards Mario

Mario,
Please refer to the Trouble SHooting section of this guide,
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/1a69ea11-0d01-0010-fa80-b47a79301290
Also, check the HTTP Connection INTEGRATION_DIRECTORY_HMI and try a test connection of this. It should return HTTP Code : 500
Regards
Bhavesh

Unable to Start Operation, Refreshing Cache. Pleas...

Hi, I have N9 and since last 3 days I am not having any download and installation also the updation. I have already updated the PR1.2 and it's fine. Only the problem when I go for new download message appears " Unable to Start Operation, Refreshing Cache, Please Wait" in the Screen.
Many many thanks in advance if anybody can advise me to resolve this issue.
Solved!
Go to Solution.

@dshiwakoti
Go to Settings > Security > Developer mode > move white dot to right and accept prompt
Launch Terminal as new icon ( ~ $) will now have appeared and type the following on each line followed by tapping enter:-
devel-su
rootme (password unless altered by user)
rm /etc/apt/sources.list.d/filemanager.list (to delete the problematic repository - note space after rm )
- Reboot the device
- Open X-Terminal
devel-su
rootme
apt-get update
Can't take credit for the above from My-Meego forums
Happy to have helped forum with a Support Ratio = 42.5

Delta refresh cache in SXI_CACHE Transactions disabled

Hi Experts!
I have SAP ECC and SAP XI installed on same SAP MMC. ECC is working fine, but the Problem is with SAP XI. When SXI_CACHE transactions executed it giving the error as "Unable to refresh the cache". and the "Delta cache" is also disabled. So any can help me pls pass on the links or answers or any gud solutions I ll b thankful for them....
THANKS IN ADVANCE!!!
Sunil K Shetty

Hi Sunil,
Check dis threads:
Unable to refresh cache contents in XI.
Error in Cache Refresh(Unable to refresh cache contents)
Cache Refresh disabled in SXI_CACHE
The problem is mentioned in the above threads.
Regards,
Prasanthi.
*Plz reward for helpful answers**

Way to refresh cache for only one service

Is there a way to refresh cache for only one service?
Rewards points guaranteed.
Regards.

Is this really a problem? Why not invalidating the cache alt all
when it seems to be necessary?
regards
Tobias

Refreshing Cache

Scenario
There are some Objects created and not activated in ID. Will refreshing the cache effect the objects created.
Regards,
-Naveen.

Hi,
Explicit Saving and activating objects is mandatory to activate the objects.I don't think activation of objects is related to refreshing cache .
Caches temporarily store data that is exchanged between components. They are used to reduce access times and to expedite the transfer of data. Refreshing the cache means, back end connections are made during the next request and the cache is validated for any new or any deleted items. Before contacting the back ends, expired items are removed from the cache.
Regards,
Mani

Refreshing cache group from C/C++ application

Hi
anyone knows how to refresh a user-managed cache group from an application developed in C or C++ (ttclasses ) ?
Please HELP !!!!!!
lewismm

Execute the relevant SQL statement ('REFRESH CACHE GROUP cgname' is the most likely one) just like you would any other SQL statement.
Chris

Refreshing cached DNS directory

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