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  • Public DNS Server fails on Windows Amazon EC2

    - by Adroidist
    I have started a new Windows server instance on Amazon EC2. The security group has the following rules: Ports Protocol Source 22 tcp 0.0.0.0/0 80 tcp 0.0.0.0/0 443 tcp 0.0.0.0/0 3389 tcp 0.0.0.0/0 53 udp 0.0.0.0/0 -1 icmp 0.0.0.0/0 I am able to ping the public DNS server of the machine and i can connect to it using Windows Remote Desktop connection. However, when i put in my web browser the public DNS server, it fails to connect. Morever, I used filezilla and putty (and in both I loaded the private key .pem) but i receive connection timed out. I disabled the firewall on both my pc and the instance (which I entered using Remote desktop connection). Can you please tell me what I am missing?

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  • Exchange 2013 - DNS Records for Accepting Multiple Domains

    - by William
    I have an Exchange 2013 server accepting two domains: domain1.com and domain2.com. All of the exchange services (OWA, ECP, POP3, SMTP, etc.) can be found via the address mail.domain1.com. So, in the DNS records for domain1, I have the following entries: MX Record mail.domain1.com A Record mail.domain1.com - (IP Address of Server) CNAME Record autodiscover.domain1.com - mail.domain1.com Now, for domain2.com, how would I set up the DNS records? Would I have the autodiscover just be a cname for autodiscover.domain1.com? Would this allow me to leverage the certificates that I have installed for domain1?

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  • Setting DNS Siffix for multiple network adapters in a VM

    - by arun_bh
    Is there a way to set the DNS Suffix for multiple network adapters in a VM using the sysprep file? We are trying to setup Windows 2003 VMs with 2 network adapters. In the one adapter case the sysprep we are able to set the suffix using DNSDomain. But this doesnt work in the 2 adapter case. The The VM is setup corrently though without any issues but one of our apps relies on the DNS Suffix value to work correctly. Thanks in advance.

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  • Excessive Outbound DNS Traffic

    - by user1318414
    I have a VPS system which I have had for 3 years on one host without issue. Recently, the host started sending an extreme amount of outbound DNS traffic to 31.193.132.138. Due to the way that Linode responded to this, I have recently left Linode and moved to 6sync. The server was completely rebuilt on 6sync with the exception of postfix mail configurations. Currently, the daemons run are as follows: sshd nginx postfix dovecot php5-fpm (localhost only) spampd (localhost only) clamsmtpd (localhost only) Given that the server was 100% rebuilt, I can't find any serious exploits against the above stated daemons, passwords have changed, ssh keys don't even exist on the rebuild yet, etc... it seems extremely unlikely that this is a compromise which is being used to DoS the address. The provided IP is noted online as a known SPAM source. My initial assumption was that it was attempting to use my postfix server as a relay, and the bogus addresses it was providing were domains with that IP registered as their nameservers. I would imagine given my postfix configuration that DNS queries for things such as SPF information would come in with equal or greater amount than the number of attempted spam e-mails sent. Both Linode and 6Sync have said that the outbound traffic is extremely disproportionate. The following is all the information I received from Linode regarding the outbound traffic: 21:28:28.647263 IP 97.107.134.33.32775 > 31.193.132.138.53: 28720 op8+% [b2&3=0x4134] [17267a] [30550q] [28773n] [14673au][|domain] 21:28:28.647264 IP 97.107.134.33 > 31.193.132.138: udp 21:28:28.647264 IP 97.107.134.33.32775 > 31.193.132.138.53: 28720 op8+% [b2&3=0x4134] [17267a] [30550q] [28773n] [14673au][|domain] 21:28:28.647265 IP 97.107.134.33 > 31.193.132.138: udp 21:28:28.647265 IP 97.107.134.33.32775 > 31.193.132.138.53: 28720 op8+% [b2&3=0x4134] [17267a] [30550q] [28773n] [14673au][|domain] 21:28:28.647266 IP 97.107.134.33 > 31.193.132.138: udp 6sync cannot confirm whether or not the recent spike in outbound traffic was to the same IP or over DNS, but I have presumed as such. For now my server is blocking the entire 31.0.0.0/8 subnet to help deter this while I figure it out. Anyone have any idea what is going on?

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  • DNS security (hijacking?)

    - by Jongsma
    I am hosting my website on Linode and am also using their DNS/naming servers. (ns1.linode.com etc.) It occurred to me that I never have had to authenticate that the domain is mine when I added it to the domain to the DNS manager, or at any other point. I now wonder whether it would be possible for other Linode users to 'hijack' my domain by simply adding the same domain zone and pointing it to their own server. I wouldn't know how Linode could determine which are the real/authentic records. How can I be sure this doesn't happen?

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  • Reverse DNS for two ADs in the same subnet

    - by SpacemanSpiff
    I currently have two separate AD forests that exist within the same subnet. The two forests have independent copies of the reverse lookup zone for that subnet. Example: Domain A DC1: 10.1.1.1/24 Domain A DC2: 10.1.1.2/24 Domain A AppServer1:10.1.1.3/24 Domain B DC1: 10.1.1.11/24 Domain B DC2: 10.1.1.12/24 Domain B Appserver1:10.1.1.13/24 What I'm after, is a configuration that allows this reverse zone to be shared between them so that both sets of DNS servers can make updates to the zone. This kind of thing is a little far from my everday work, so a kick in the right direction is a welcome suggestion as well. Decoupling one AD into new segments is a possibility I'm open to but would like to avoid if possible. If there is a DNS related solution I'd prefer that.

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  • Relation between Apache and DNS configuration

    - by KayKay
    I configured my DNS (bind9) to accept every subdomain, using a wildcarded 'A' record : *.mydomain.tld. IN A xx.xx.xx.xx I configured Apache to serve some specific subdomains using virtual hosts : <VirtualHost *:80> ServerName sub1.mydomain.tld ServerAlias sub1.mydomain.tld JkMount / sub1JK JkMount /* sub1JK </VirtualHost> when I ping from a remote computer on a subdomain configured in apache I get a response. When I ping on a subdomain that is not configured in apache, the host is not found. I don't understand why apache configuration would affect DNS resolution like this? I would appreciate any information that helps me understand this. Thanks a lot.

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  • Google Cloud DNS and DNSSEC?

    - by Joe Burnett
    Since Google Cloud DNS does not currently support the record types for DNSSEC, is there any way to begin implementation of DNSSEC using TXT records? If I were using Google Cloud DNS, which I am, and they currently only support record types which include SOA, A, AAAA, CNAME, MX, NS, SPF, SRV, PTR and TXT: am I able to do it while constricted to these record types? Or do I have to wait until support is hard-coded into the service? I am just wondering because I would really like to ensure absolute integrity for my company so that I only convey realness in it's purity. =D

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  • Update a DNS to a for a dynamic IP

    - by zobgib
    I want to use my schools connection as a place to host a small webserver but one problem I have run into is anytime my server reboots I am given a new IP inside the schools range. All of the schools IP are public and therefor I can access my computer directly over WAN just via the IP given in ifconfig. I would like to be able to give my computer a dns which is easy enough when I change the Arecords to match the current IP of my computer. The problem is if my computer ever reboots (my school regularly cycles power at night and over holidays) I am assigned a new IP and have to realize it then update the Arecords This is inconvenient and I figure there must be a better way to keep the DNS records updated either via a script or my own BIND server. That way if there is a power cycle I can still access the server via a Domain Name. If you have any direction to point me in it would be much appreciated. I am running Ubuntu 10.04 if that helps :).

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  • Empty AAAA DNS Record with long TTL?

    - by Joel K
    I pay for a DNS service based on queries per second. We are not using IPv6, but a large number of queries (that I pay for) are coming in for AAAA records. I understand that most DNS stacks will now ask for A and AAAAs at the same time, and that I can't change that. What I /would/ like to do is put something in the AAAA records with a long TTL. (decreasing my hit rate) Is there anything I can put? Null? The equivalent IPv4 Address? Any guidance would be appreciated.

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  • pfSense router gives DNS rebinding warning when accessing subdomains

    - by Richard Maddis
    I have just set up a router running pfSense on our network and forwarded the appropriate ports. I have a small web server running in my network, and a domain name pointing to our (WAN) IP. When accessing that domain name, everything works fine. However, when accessing a subdomain of the domain name, pfSense will give a DNS rebinding warning. This did not happen back when I used a DD-WRT router. What is the proper way to fix this? The DNS records for the subdomain also point to the same address (I use a virtual server to differentiate the subdomains.)

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  • DNS problems : correct nameserver, namserver working, but not resolving

    - by user1719624
    My problem is as follows. Any suggestions are welcome. [domain].org is not resolving whois and checking the registry information shows that the correct nameserver is set. The primary nameserver is also the server on which domain.org is hosted. The primary nameserver is also used for a number of other domains, and is working fine for those. Logging into the server, I can ping [domain].org and it resolves correctly. Setting the nameserver as my own DNS server on my laptop, and the URL resolves correctly. If the domain has the correct nameserver set, and the nameserver can resolve the URL to the correct IP address, and if I use the nameserver as my DNS then it resolves correctly, AND the nameserver is used for other domains which are resolving correctly, then why isn't it working? NB : this is a new domain registration and has been set up for around 10 days now, so it's not simple slow propagation. Any ideas? thanks

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  • What TLDs should I use for my NS records for redundancy? (DNSSEC support required)

    - by makerofthings7
    Question As a general practice, is it a good idea to use multiple TLDs for the name servers? How should I choose between which TLD would be a good candidate for being the root server for my NS name? More Info I am switching over 800 DNS zones to an outsourced DNS provider. I originally planned on setting the zone names to nsX.company.com, but think it would be best to have multiple TLDs such as .net , .org and .info Since I plan on supporting DNSSec at company.com I think all the 1st tier Name servers must support it as well. Part of the inspiration for this question came from our provider UltraDNS. In their configuration screen for our domains, they actively verify and alert us if our name servers aren't exactly: pdns1.ultradns.net pdns2.ultradns.net pdns3.ultradns.org pdns4.ultradns.org pdns5.ultradna.info pdns6.ultradns.co.uk

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  • Disable Network settings (TCP/IP & DNS) on Windows 7 Ultimate

    - by TiD91
    i also read this discussion here How to disable Tcp/Ip settings in windows 7 via GPO? about what i want to do but i still have problems. So here i am: i have a desktop pc with two accounts, both with Administrative rights. One is used by the entire my family, in particular by my brother. The problem is that i set some DNS and IP configurations to let be possible the VNC connection from remote. Now i would like to disable the network settings (TCP/IP and DNS) to prohibit my brother to change it preventing me to connect to it. So how can i do this? I set the policies from GPO but i still can change these settings from his account. Here's a pic of Registry Keys: http://imageshack.us/a/img339/3310/famigliapc2012092017274.png what didn't i do? Thanks in advance for your help. Rub|TiD

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  • QPS for dnscache

    - by vedaprasad
    I have 2 internal DNS servers ( ns1 & ns 2 ) on ubuntu 12.04 which run dnscache , and my clients resolv.conf have something like nameserver ns1 nameserver ns2 nameserver 8.8.8.8 since all my load is taken by ns1 , where as ns2 sits idle until ns1 is down or not serving my request . i would like to add these 2 server under a LB VIP . but my network team wants to know the QPS of the ns servers so that their LB is loaded . so is there any way to find out the QPS of dns queries running Dncache

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  • Configuring a backup DNS server

    - by mattyh88
    I would like to setup a backup DNS server. I have added all my name servers in my domain name panel. (ns1.domain.com, ns2.domain.com, etc ...) If a person would try to go to domain.com and the first name server would fail, will it automatically try and use ns2.domain.com? All my DNS servers have the same master zones configured. Is that the way to go? Is it that easy or am I missing something here? :)

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  • Content Management for WebCenter Installation Guide

    - by Gary Niu
    Overvew As we known, there are two way to install Content Management for WebCenter. One way is install it by WebCenter installer wizard, another way is to install it use their own installer. This guide is for the later one. For SSO purpose, I also mentioned how to config OID identity store for Content Management for WebCenter. Content Management for WebCenter( 10.1.3.5.1) Oracle Enterprise Linux R5U4 Basic Installation -bash-3.2$ ./setup.sh Please select your locale from the list.           1. Chinese-Simplified           2. Chinese-Traditional           3. Deutsch          *4. English-US           5. English-UK           6. Español           7. Français           8. Italiano           9. Japanese          10. Korean          11. Nederlands          12. Português-Brazil Choice? Throughout the install, when entering a text value, you can press Enter to accept the default that appears between square brackets ([]). When selecting from a list, you can select the choice followed by an asterisk by pressing Enter. Select installation type from the list.         *1. Install new server          2. Update a server Choice? Content Server Installation Directory Please enter the full pathname to the installation directory. Content Server Core Folder [/oracle/ucm/server]:/opt/oracle/ucm/server Create Directory         *1. yes          2. no Choice? Java virtual machine         *1. Sun Java 1.5.0_11 JDK          2. Specify a custom Java virtual machine Choice? Installing with Java version 1.5.0_11. Enter the location of the native file repository. This directory contains the native files checked in by contributors. Content Server Native Vault Folder [/opt/oracle/ucm/server/vault/]: Create Directory         *1. yes          2. no Choice? Enter the location of the web-viewable file repository. This directory contains files that can be accessed through the web server. Content Server Weblayout Folder [/opt/oracle/ucm/server/weblayout/]: Create Directory         *1. yes          2. no Choice? This server can be configured to manage its own authentication or to allow another master to act as an authentication proxy. Configure this server as a master or proxied server.         *1. Configure as a master server.          2. Configure as server proxied by a local master server. Choice? During installation, an admin server can be installed and configured to manage this server. If there is already an admin server on this system, you can have the installer configure it to administrate this server instead. Select admin server configuration.         *1. Install an admin server to manage this server.          2. Configure an existing admin server to manage this server.          3. Don't configure an admin server. Choice? Enter the location of an executable to start your web browser. This browser will be used to display the online help. Web Browser Path [/usr/bin/firefox]: Content Server System locale           1. Chinese-Simplified           2. Chinese-Traditional           3. Deutsch          *4. English-US           5. English-UK           6. Español           7. Français           8. Italiano           9. Japanese          10. Korean          11. Nederlands          12. Português-Brazil Choice? Please select the region for your timezone from the list.         *1. Use the timezone setting for your operating system          2. Pacific          3. America          4. Atlantic          5. Europe          6. Africa          7. Asia          8. Indian          9. Australia Choice? Please enter the port number that will be used to connect to the Content Server. This port must be otherwise unused. Content Server Port [4444]: Please enter the port number that will be used to connect to the Admin Server. This port must be otherwise unused. Admin Server Port [4440]: Enter a security filter for the server port. Hosts which are allowed to communicate directly with the server port may access any resources managed by the server. Insure that hosts which need access are included in the filter. See the installation guide for more details. Incoming connection address filter [127.0.0.1]:*.*.*.* *** Content Server URL Prefix The URL prefix specified here is used when generating HTML pages that refer to the contents of the weblayout directory within the installation. This prefix must be mapped in the web server Additional Document Directories section of the Content Management administration menu to the physical location of the weblayout directory. For example, "/idc/" would be used in your installation to refer to the URL http://ucm.company.com/idc which would be mapped in the web server to the physical location /oracle/ucm/server/weblayout. Web Server Relative Root [/idc/]: Enter the name of the local mail server. The server will contact this system to deliver email. Company Mail Server [mail]: Enter the e-mail address for the system administrator. Administrator E-Mail Address [sysadmin@mail]: *** Web Server Address Many generated HTML pages refer to the web server you are using. The address specified here will be used when generating those pages. The address should include the host and domain name in most cases. If your webserver is running on a port other than 80, append a colon and the port number. Examples: www.company.com, ucm.company.com:90 Web Server HTTP Address [yekki]:yekki.cn.oracle.com:7777 Enter the name for this instance. This name should be unique across your entire enterprise. It may not contain characters other than letters, numbers, and underscores. Server Instance Name [idc]: Enter a short label for this instance. This label is used on web pages to identify this instance. It should be less than 12 characters long. Server Instance Label [idc]: Enter a long description for this instance. Server Description [Content Server idc]: Web Server         *1. Apache          2. Sun ONE          3. Configure manually Choice? Please select a database from the list below to use with the Content Server. Content Server Database         *1. Oracle          2. Microsoft SQL Server 2005          3. Microsoft SQL Server 2000          4. Sybase          5. DB2          6. Custom JDBC settings          7. Skip database configuration Choice? Manually configure JDBC settings for this database          1. yes         *2. no Choice? Oracle Server Hostname [localhost]: Oracle Listener Port Number [1521]: *** Database User ID The user name is used to log into the database used by the content server. Oracle User [user]:YEKKI_OCSERVER *** Database Password The password is used to log into the database used by the content server. Oracle Password []:oracle Oracle Instance Name [ORACLE]:orcl Configure the JVM to find the JDBC driver in a specific jar file          1. yes         *2. no Choice? The installer can attempt to create the database tables or you can manually create them. If you choose to manually create the tables, you should create them now. Attempt to create database tables          1. yes         *2. no Choice? Select components to install.          1. ContentFolios: Collect related items in folios          2. Folders_g: Organize content into hierarchical folders          3. LinkManager8: Hypertext link management support          4. OracleTextSearch: External Oracle 11g database as search indexer support          5. ThreadedDiscussions: Threaded discussion management Enter numbers separated by commas to toggle, 0 to unselect all, F to finish: 1,2,3,4,5         *1. ContentFolios: Collect related items in folios         *2. Folders_g: Organize content into hierarchical folders         *3. LinkManager8: Hypertext link management support         *4. OracleTextSearch: External Oracle 11g database as search indexer support         *5. ThreadedDiscussions: Threaded discussion management Enter numbers separated by commas to toggle, 0 to unselect all, F to finish: F Checking configuration. . . Configuration OK. Review install settings. . . Content Server Core Folder: /opt/oracle/ucm/server Java virtual machine: Sun Java 1.5.0_11 JDK Content Server Native Vault Folder: /opt/oracle/ucm/server/vault/ Content Server Weblayout Folder: /opt/oracle/ucm/server/weblayout/ Proxy authentication through another server: no Install admin server: yes Web Browser Path: /usr/bin/firefox Content Server System locale: English-US Content Server Port: 4444 Admin Server Port: 4440 Incoming connection address filter: *.*.*.* Web Server Relative Root: /idc/ Company Mail Server: mail Administrator E-Mail Address: sysadmin@mail Web Server HTTP Address: yekki.cn.oracle.com:7777 Server Instance Name: idc Server Instance Label: idc Server Description: Content Server idc Web Server: Apache Content Server Database: Oracle Manually configure JDBC settings for this database: false Oracle Server Hostname: localhost Oracle Listener Port Number: 1521 Oracle User: YEKKI_OCSERVER Oracle Password: 6GP1gBgzSyKa4JW10U8UqqPznr/lzkNn/Ojf6M8GJ8I= Oracle Instance Name: orcl Configure the JVM to find the JDBC driver in a specific jar file: false Attempt to create database tables: no Components: ContentFolios,Folders_g,LinkManager8,OracleTextSearch,ThreadedDiscussions Proceed with install         *1. Proceed          2. Change configuration          3. Recheck the configuration          4. Abort installation Choice? Finished install type Install with warnings at 4/2/10 12:32 AM. Run Scripts -bash-3.2$ ./wc_contentserverconfig.sh /opt/oracle/ucm/server /mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf Installing '/mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf/CS10gR35UpdateBundle.zip' Service 'DELETE_DOC' Extended Service 'DELETE_BYREV_REVISION' Extended Installing '/mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf/ContentAccess/ContentAccess-linux.zip' (internal)      04.02 00:40:38.019      main    updateDocMetaDefinitionV11: adding decimal column Installing '/opt/oracle/ucm/server/custom/CS10gR35UpdateBundle/extras/Folders_g.zip' Installing '/opt/oracle/ucm/server/custom/CS10gR35UpdateBundle/extras/FusionLibraries.zip' Installing '/opt/oracle/ucm/server/custom/CS10gR35UpdateBundle/extras/JpsUserProvider.zip' Installing '/mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf/WcConfigure.zip' Apr 2, 2010 12:41:24 AM oracle.security.jps.internal.core.util.JpsConfigUtil getPasswordCredential WARNING: A password credential is expected; instead found . Apr 2, 2010 12:41:24 AM oracle.security.jps.internal.idstore.util.IdentityStoreUtil getUnamePwdFromCredStore WARNING: The credential with map JPS and key ldap.credential does not exist. Apr 2, 2010 12:41:27 AM oracle.security.jps.internal.core.util.JpsConfigUtil getPasswordCredential WARNING: A password credential is expected; instead found . Apr 2, 2010 12:41:27 AM oracle.security.jps.internal.idstore.util.IdentityStoreUtil getUnamePwdFromCredStore WARNING: The credential with map JPS and key ldap.credential does not exist. Apr 2, 2010 12:41:28 AM oracle.security.jps.internal.core.util.JpsConfigUtil getPasswordCredential WARNING: A password credential is expected; instead found . Apr 2, 2010 12:41:28 AM oracle.security.jps.internal.idstore.util.IdentityStoreUtil getUnamePwdFromCredStore WARNING: The credential with map JPS and key ldap.credential does not exist. Restart Content Server to apply updates. Configuring Apache Web Server append the following lines at httpd.conf: include "/opt/oracle/ucm/server/data/users/apache22/apache.conf" Configuring the Identity Store( Optional ) 1.  Stop Oracle Content Server and the Admin Server 2.  Update the Oracle Content Server's JPS configuration file, jps-config.xml: a. add a service instance <serviceInstance provider="idstore.ldap.provider" name="idstore.oid"> <property name="subscriber.name" value="dc=cn,dc=oracle,dc=com"></property> <property name="idstore.type" value="OID"></property> <property name="security.principal.key" value="ldap.credential"></property> <property name="security.principal.alias" value="JPS"></property> <property name="ldap.url" value="ldap://yekki.cn.oracle.com:3060"></property> <extendedProperty> <name>user.search.bases</name> <values> <value>cn=users,dc=cn,dc=oracle,dc=com</value> </values> </extendedProperty> <extendedProperty> <name>group.search.bases</name> <values> <value>cn=groups,dc=cn,dc=oracle,dc=com</value> </values> </extendedProperty> <property name="username.attr" value="uid"></property> <property name="user.login.attr" value="uid"></property> <property name="groupname.attr" value="cn"></property> </serviceInstance> b. Ensure that the <jpsContext> entry in the jps-config.xml file refers to the new serviceInstance, that is, idstore.oid and not idstore.ldap: <jpsContext name="default"> <serviceInstanceRef ref="idstore.oid"/> 3. Run the new script to setup the credentials for idstore.oid in the credential store: cd CONTENT_SERVER_HOME/custom/FusionLibraries/tools -bash-3.2$ ./run_credtool.sh Buildfile: ./../tools/credtool.xml     [input] skipping input as property action has already been set.     [input] Alias: [JPS]     [input] Key: [ldap.credential]     [input] User Name: cn=orcladmin     [input] Password: welcome1     [input] JPS Config: [/opt/oracle/ucm/server/custom/FusionLibraries/tools/../../../config/jps-config.xml] manage-creds:      [echo] @@@ Help: run 'ant manage-creds' command to see the detailed usage      [java] Using default context in /opt/oracle/ucm/server/custom/FusionLibraries/tools/../../../config/jps-config.xml file for credential store.      [java] Credential store location : /opt/oracle/ucm/server/config      [java] Credential with map JPS key ldap.credential stored successfully!      [java]      [java]      [java]     Credential for map JPS and key ldap.credential is:      [java]             PasswordCredential name : cn=orcladmin      [java]             PasswordCredential password : welcome1 BUILD SUCCESSFUL Total time: 1 minute 27 seconds Testing 1. acces http://yekki.cn.oracle.com:7777/idc 2. login in with OID user, for example: orcladmin/welcome1 3. make sure your JpsUserProvider status is "good"

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  • SQL SERVER – Subquery or Join – Various Options – SQL Server Engine knows the Best

    - by pinaldave
    This is followup post of my earlier article SQL SERVER – Convert IN to EXISTS – Performance Talk, after reading all the comments I have received I felt that I could write more on the same subject to clear few things out. First let us run following four queries, all of them are giving exactly same resultset. USE AdventureWorks GO -- use of = SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID = ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA WHERE EA.EmployeeID = E.EmployeeID) GO -- use of in SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID IN ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA WHERE EA.EmployeeID = E.EmployeeID) GO -- use of exists SELECT * FROM HumanResources.Employee E WHERE EXISTS ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA WHERE EA.EmployeeID = E.EmployeeID) GO -- Use of Join SELECT * FROM HumanResources.Employee E INNER JOIN HumanResources.EmployeeAddress EA ON E.EmployeeID = EA.EmployeeID GO Let us compare the execution plan of the queries listed above. Click on image to see larger image. It is quite clear from the execution plan that in case of IN, EXISTS and JOIN SQL Server Engines is smart enough to figure out what is the best optimal plan of Merge Join for the same query and execute the same. However, in the case of use of Equal (=) Operator, SQL Server is forced to use Nested Loop and test each result of the inner query and compare to outer query, leading to cut the performance. Please note that here I no mean suggesting that Nested Loop is bad or Merge Join is better. This can very well vary on your machine and amount of resources available on your computer. When I see Equal (=) operator used in query like above, I usually recommend to see if user can use IN or EXISTS or JOIN. As I said, this can very much vary on different system. What is your take in above query? I believe SQL Server Engines is usually pretty smart to figure out what is ideal execution plan and use it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Joins, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Subquery or Join – Various Options – SQL Server Engine Knows the Best – Part 2

    - by pinaldave
    This blog post is part 2 of the earlier written article SQL SERVER – Subquery or Join – Various Options – SQL Server Engine knows the Best by Paulo R. Pereira. Paulo has left excellent comment to earlier article once again proving the point that SQL Server Engine is smart enough to figure out the best plan itself and uses the same for the query. Let us go over his comment as he has posted. “I think IN or EXISTS is the best choice, because there is a little difference between ‘Merge Join’ of query with JOIN (Inner Join) and the others options (Left Semi Join), and JOIN can give more results than IN or EXISTS if the relationship is 1:0..N and not 1:0..1. And if I try use NOT IN and NOT EXISTS the query plan is different from LEFT JOIN too (Left Anti Semi Join vs. Left Outer Join + Filter). So, I found a case where EXISTS has a different query plan than IN or ANY/SOME:” USE AdventureWorks GO -- use of SOME SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID = SOME ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA UNION ALL SELECT EA.EmployeeID FROM HumanResources.EmployeeDepartmentHistory EA ) -- use of IN SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID IN ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA UNION ALL SELECT EA.EmployeeID FROM HumanResources.EmployeeDepartmentHistory EA ) -- use of EXISTS SELECT * FROM HumanResources.Employee E WHERE EXISTS ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA UNION ALL SELECT EA.EmployeeID FROM HumanResources.EmployeeDepartmentHistory EA ) When looked into execution plan of the queries listed above indeed we do get different plans for queries and SQL Server Engines creates the best (least cost) plan for each query. Click on image to see larger images. Thanks Paulo for your wonderful contribution. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, Readers Contribution, SQL, SQL Authority, SQL Joins, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Concat Function in SQL Server – SQL Concatenation

    - by pinaldave
    Earlier this week, I was delivering Advanced BI training on the subject of “SQL Server 2008 R2″. I had great time delivering the session. During the session, we talked about SQL Server 2010 Denali. Suddenly one of the attendees suggested his displeasure for the product. He said, even though, SQL Server is now in moving very fast and have proved many times a good enterprise solution, it does not have some basic functions. I naturally asked him for example and he suggested CONCAT() which exists in MySQL and Oracle. The answer is very simple – the equalent function in SQL Server to CONCAT() is ‘+’ (plus operator without quotes). Method 1: Concatenating two strings SELECT 'FirstName' + ' ' + 'LastName' AS FullName Method 2: Concatenating two Numbers SELECT CAST(1 AS VARCHAR(10)) + 'R' + CAST(2 AS VARCHAR(10)) Method 3: Concatenating values from table columns SELECT FirstName + ' ' + LastName FROM AdventureWorks.Person.Contact Well, this may look very simple but sometime it is very difficult to find the information for simple things only. Do you have any such example which you would like to share with community? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL String, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – List All the DMV and DMF on Server

    - by pinaldave
    “How many DMVs and DVFs are there in SQL Server 2008?” – this question was asked to me in one of the recent SQL Server Trainings. Answer is very simple: SELECT name, type, type_desc FROM sys.system_objects WHERE name LIKE 'dm_%' ORDER BY name Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL DMV

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  • An XEvent a Day (19 of 31) – Using Customizable Fields

    - by Jonathan Kehayias
    Today’s post will be somewhat short, but we’ll look at Customizable Fields on Events in Extended Events and how they are used to collect additional information.  Customizable Fields generally represent information of potential interest that may be expensive to collect, and is therefore made available for collection if specified by the Event Session.  In SQL Server 2008 and 2008 R2, there are 50 Events that have customizable columns in their payload.  In SQL Server Denali CTP1, there...(read more)

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  • An XEvent a Day (5 of 31) - Targets Week – ring_buffer

    - by Jonathan Kehayias
    Yesterday’s post, Querying the Session Definition and Active Session DMV’s , showed how to find information about the Event Sessions that exist inside a SQL Server and how to find information about the Active Event Sessions that are running inside a SQL Server using the Session Definition and Active Session DMV’s.  With the background information now out of the way, and since this post falls on the start of a new week I’ve decided to make this Targets Week, where each day we’ll look at a different...(read more)

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  • SQL Server Driver for PHP 2.0 CTP adds PHP's PDO style data access for SQL Server

    - by The Official Microsoft IIS Site
    Today at DrupalCon SF 2010, we are reaching an important milestone by releasing a Community Technology Preview (CTP) of the new SQL Server Driver for PHP 2.0 , which includes support for PHP Data Objects (PDO). Alongside our efforts, the Commerce Guys , a company providing ecommerce solutions with Drupal, is also presenting a beta version of Drupal 7 running on SQL Server using this new PDO Application Programming Interfaces (API) in the SQL Server Driver for PHP 2.0. Providing a PDO driver in SQL...(read more)

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