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• cocos2d - how to draw a bottle sprite with dynamically changing water level

  - by Oliver

  I am trying to draw a (2d) sprite in cocos2d showing a bottle. The bottle shall be able to have a dynamic water level (i.e. the amount of water in the bottle can change over the lifetime of the sprite). I am wondering how to do this. I currently have a PNG file of the empty bottle. I adjusted the alpha channel of that PNG so when rendering the sprite I can draw a blue rectangle and render the bottle texture over it. That will give the impression of the water being inside the bottle. However, the bottle's shape is not a rectangle itself of course, so the water can be seen out of the bounds of the bottle. I can change the bottle image in a way that only the bottle itself is transparent and set the "outside world" to an opaque color & alpha channel value, but that again prevents the "world background" to be visible in that area. I simply don't have a clue how to realize this in a sane manner. Do I really have to read every pixel of the bottle image, identify which pixel is "inside" of the bottle and then draw the water pixel by pixel? There must be an easier way, right? ;) Any best practices for these kinds of tasks? edit: see picture below, to make somewhat clearer, what I am talking about ;) http://i47.tinypic.com/10rqww0.png

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• Linq Return node level of hierarchical xml

  - by Ryan

  In a treeview you can retrieve the level of an item. I am trying to accomplish the same thing with the given input being an object. The XML data I will use for this example would be something like the following <?xml version="1.0" encoding="utf-8" ?> <Testing> <Numbers> <Number val="1"> <Number val="1.1"> <Number val="1.1.1"> <Number val="1.1.2" /> <Number val="1.1.3" /> <Number val="1.1.4" /> </Number> </Number> <Number val="1.2" /> <Number val="1.3" /> <Number val="1.4" /> </Number> <Number val="2" /> <Number val="3" /> <Number val="4" /> </Numbers> <Numbers> <Number val="5" /> <Number val="6" /> <Number val="7" /> <Number val="8" /> </Numbers> </Testing> This one is kicking my butt!

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• PHP dynamic Page-level DocBlocks

  - by Obmerk Kronen

  I was wondering if there is a way to interact with the Page-level DocBlocks. My question is more specifically about wordpress plugin development, but this question has arised also in a non-wordpress environments. The reason is mainly the possibility to easily change VERSIONS and names throughout a large project with maybe a constant definition - but that will reflect also in the docblock.. The following example Docblock is from a wordpress plugin I write - /* Plugin Name: o99 Auxilary Functions v0.4.7 Plugin URI: http://www.myurl.com Description: some simple description that nobody reads. Version: 0.4.7 Author: my cool name Author URI: http://www.ok-alsouri.com */ Is there a way to transform it into : $ver = '0.4.7'; $uri = 'http://www.myurl.com'; $desc = 'some simple description that nobody reads.'; $mcn = 'my cool name'; etc.. etc.. /* Plugin Name: o99 Auxilary Functions ($ver) Plugin URI: ($uri) Description: ($desc) Version: ($ver) Author: ($mcn) Author URI: ($$uri) */ obviously for echo to work I would need to break the docblock itself, and I can not WRITE the docblock directly into it´s own file . In shorts : can I "generate" a docblock with php itself somehow (I would think that the answer is - "no" for the page itself.. But maybe I am wrong and someone has some neat hack :-) ) Is that even possible ?

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• Return node level of hierarchical xml

  - by Ryan

  In a treeview you can retrieve the level of an item. I am trying to accomplish the same thing with the given input being an object. The XML data I will use for this example would be something like the following <?xml version="1.0" encoding="utf-8" ?> <Testing> <Numbers> <Number val="1"> <Number val="1.1"> <Number val="1.1.1"> <Number val="1.1.2" /> <Number val="1.1.3" /> <Number val="1.1.4" /> </Number> </Number> <Number val="1.2" /> <Number val="1.3" /> <Number val="1.4" /> </Number> <Number val="2" /> <Number val="3" /> <Number val="4" /> </Numbers> <Numbers> <Number val="5" /> <Number val="6" /> <Number val="7" /> <Number val="8" /> </Numbers> </Testing> This one is kicking my butt!

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• Need help manipulating WAV (RIFF) Files at a byte level

  - by Eric

  I'm writing an an application in C# that will record audio files (*.wav) and automatically tag and name them. Wave files are RIFF files (like AVI) which can contain meta data chunks in addition to the waveform data chunks. So now I'm trying to figure out how to read and write the RIFF meta data to and from recorded wave files. I'm using NAudio for recording the files, and asked on their forums as well on SO for way to read and write RIFF tags. While I received a number of good answers, none of the solutions allowed for reading and writing RIFF chunks as easily as I would like. But more importantly I have very little experience dealing with files at a byte level, and think this could be a good opportunity to learn. So now I want to try writing my own class(es) that can read in a RIFF file and allow meta data to be read, and written from the file. I've used streams in C#, but always with the entire stream at once. So now I'm little lost that I have to consider a file byte by byte. Specifically how would I go about removing or inserting bytes to and from the middle of a file? I've tried reading a file through a FileStream into a byte array (byte[]) as shown in the code below. System.IO.FileStream waveFileStream = System.IO.File.OpenRead(@"C:\sound.wav"); byte[] waveBytes = new byte[waveFileStream.Length]; waveFileStream.Read(waveBytes, 0, waveBytes.Length); And I could see through the Visual Studio debugger that the first four byte are the RIFF header of the file. But arrays are a pain to deal with when performing actions that change their size like inserting or removing values. So I was thinking I could then to the byte[] into a List like this. List<byte> list = waveBytes.ToList<byte>(); Which would make any manipulation of the file byte by byte a whole lot easier, but I'm worried I might be missing something like a class in the System.IO name-space that would make all this even easier. Am I on the right track, or is there a better way to do this? I should also mention that I'm not hugely concerned with performance, and would prefer not to deal with pointers or unsafe code blocks like this guy. If it helps at all here is a good article on the RIFF/WAV file format.

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• How to return a property name when comparing two properties at class-level

  - by CodeMonkey

  Hi I have implemented an 'EqualTo' Validation Attribute, that compares two Properties of an object, during ModelBinding in ASP.NET MVC 2. The problem I have is not with it not working, because it does work. The problem is, when I do my request - which is an ajax request - I get back errors to my front-end, where it sets a class on the input fields to indicate invalid input. What it does is iterate through a list of Errors (in a JsonResult), and set a class. This is all dandy. But the ValidationAtrribute I am having trouble with is set at a Class-level, i.e., it's not like other ValidationAttributes where you set something like "[Required]" or something like that. [AttributeUsage(AttributeTargets.Class, AllowMultiple=true, Inherited=false)] public class EqualToAttribute : ValidationAttribute { public String SourceProperty { get; set; } public String MatchProperty { get; set; } public EqualToAttribute(string source, string match) { SourceProperty = source; MatchProperty = match; } public override Boolean IsValid(Object value) { Type objectType = value.GetType(); PropertyInfo[] properties = objectType.GetProperties(); object sourceValue = new object(); object matchValue = new object(); Type sourceType = null; Type matchType = null; int counter = 0; foreach (PropertyInfo propertyInfo in properties) { if (propertyInfo.Name == SourceProperty || propertyInfo.Name == MatchProperty) { if (counter == 0) { sourceValue = propertyInfo.GetValue(value, null); sourceType = propertyInfo.GetValue(value, null).GetType(); } if (counter == 1) { matchValue = propertyInfo.GetValue(value, null); matchType = propertyInfo.GetValue(value, null).GetType(); } counter++; if (counter == 2) { break; } } } if (sourceType != null && matchType != null) { return sourceValue.ToString().Equals(matchValue.ToString()); //return Convert.ChangeType(sourceValue, sourceType) == Convert.ChangeType(matchValue, matchType); } return false; } private object _typeId = new object(); public override object TypeId { get { return this._typeId; } } } Now this code works, except for the fact that the validation process does not return which Property failed. And I simply can't figure out how to make it return one of the two. In reality I don't care which one it returns.. because both are failing.. Do you have an idea how to make it return the/or both Property/Properties that is/are failing.

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• Getting level values from PCM raw data using Core Audio

  - by John

  I am trying to extract level data from a PCM audio file using core audio. I have gotten as far as (I believe) getting the raw data into a byte array (UInt8) but it is 16 bit PCM data and I am having trouble reading the data out. The input is from the iPhone microphone, which I have set as: [recordSetting setValue:[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey]; [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey]; [recordSetting setValue:[NSNumber numberWithInt:1] forKey:AVNumberOfChannelsKey]; [recordSetting setValue:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey]; [recordSetting setValue:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey]; [recordSetting setValue:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey]; which is obviously 16 bits. I am then trying to just print out a few values to see if they look reasonable for debug purposes below, and they do not look reasonable (many 0's). ExtAudioFileRef inputFile = NULL; ExtAudioFileOpenURL(track.location, &inputFile); AudioStreamBasicDescription inputFileFormat; UInt32 dataSize = (UInt32)sizeof(inputFileFormat); ExtAudioFileGetProperty(inputFile, kExtAudioFileProperty_FileDataFormat, &dataSize, &inputFileFormat); UInt8 *buffer = malloc(BUFFER_SIZE); AudioBufferList bufferList; bufferList.mNumberBuffers = 1; bufferList.mBuffers[0].mNumberChannels = 1; bufferList.mBuffers[0].mData = buffer; //pointer to buffer of audio data bufferList.mBuffers[0].mDataByteSize = BUFFER_SIZE; //number of bytes in the buffer while(true) { UInt32 frameCount = (bufferList.mBuffers[0].mDataByteSize / inputFileFormat.mBytesPerFrame); // Read a chunk of input OSStatus status = ExtAudioFileRead(inputFile, &frameCount, &bufferList); // If no frames were returned, conversion is finished if(0 == frameCount) break; NSLog(@"---"); int16_t *bufferl = &buffer; for(int i=0;i<100;i++){ //const int16_t *bufferl = bufferl[i]; NSLog(@"%d",bufferl[i]); } } Not sure what I am doing wrong, I think it has to do with reading the byte array. Sorry for the long code post...

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• Cannot use READPAST in snapshot isolation mode

  - by Marcus

  I have a process which is called from multiple threads which does the following: Start transaction Select unit of work from work table with by finding the next row where IsProcessed=0 with hints (UPDLOCK, HOLDLOCK, READPAST) Process the unit of work (C# and SQL stored procedures) Commit the transaction The idea of this is that a thread dips into the pool for the "next" piece of work, and processes it, and the locks are there to ensure that a single piece of work is not processed twice. (the order doesn't matter). All this has been working fine for months. Until today that is, when I happened to realise that despite enabling snapshot isolation and making it the default at the database level, the actual transaction creation code was manually setting an isolation level of "ReadCommitted". I duly changed that to "Snapshot", and of course immediately received the "You can only specify the READPAST lock in the READ COMMITTED or REPEATABLE READ" error message. Oops! The main reason for locking the row was to "mark the row" in such a way that the "mark" would be removed when the transaction that applied the mark was committed and the lock seemed to be the best way to do this, since this table isn't read otherwise except by these threads. If I were to use the IsProcessed flag as the lock, then presumably I would need to do the update first, and then select the row I just updated, but I would need to employ the NOLOCK flag to know whether any other thread had set the flag on a row. All sounds a bit messy. The easiest option would be to abandon the snapshot isolation mode altogether, but the design of step #3 requires it. Any bright ideas on the best way to resolve this problem? Thanks Marcus

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• Books and resources for Java Performance tuning - when working with databases, huge lists

  - by Arvind

  Hi All, I am relatively new to working on huge applications in Java. I am working on a Java web service which is pretty heavily used by various clients. The service basically queries the database (hibernate) and then works with a lot of Lists (there are adapters to convert list returned from DB to the interface which the service publishes) and I am seeing lot of issues with the service like high CPU usage or high heap space. While I can troubleshoot the performance issues using a profiler, I want to actually learn about what all I need to take care when I actually write code. Like what kind of List to use or things like using StringBuilder instead of String, etc... Is there any book or blogs which I can refer which will help me while I write new services? Also my application is multithreaded - each service call from a client is a new thread, and I want to know some best practices around that area as well. I did search the web but I found many tips which are not relevant in the latest Java 6 releases, so wanted to know what kind of resources would help a developer starting out now on Java for heavily used applications. Arvind

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• heartbeat: Bad nodename in /etc/ha.d//haresources [node1]

  - by Richard

  I'm trying to start heartbeat on Ubuntu 10.04 with service heartbeat start, but getting the following errors: heartbeat[24829]: 2011/11/22_19:31:07 ERROR: Bad nodename in /etc/ha.d//haresources [node1] heartbeat[24829]: 2011/11/22_19:31:07 ERROR: Configuration error, heartbeat not started. On on server uname -n produces loadb1, on the second server uname -n produces loadb2. The two servers can ping each other okay with those names. This is /etc/ha.d/ha.cnf on both servers: debugfile /var/log/ha-debug logfile /var/log/ha-log logfacility local0 keepalive 2 deadtime 10 udpport 694 bcast eth1 ucast eth0 my.external.ip ucast eth0 my.external.ip ucast eth1 10.0.0.5 ucast eth1 10.0.0.6 #udp eth0 node loadb1 node loadb2 auto_failback off And this is /etc/ha.d/haresources on both servers: node1 IPaddr::46.20.121.113 httpd smb dhcpd Authkeys is also set up. What am I doing wrong? The part where I'm least clear is the ucast/bcast lines.

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• Exchange 2010 DAG Automatic Failover Testing/Issue. Not always automatically failing over to health

  - by Richard

  Ok I've got 2 exchange 2010 servers that run client access/hub transport/mailbox roles and one exchange 2010 server running just client access/hub transport roles and acts as my bridgehead. The two mailbox servers are running one database setup in a DAG. Server A shows the DB Mounted and Server B shows Healthy. If I reboot Server A via windows GUI Server B switches from healthy to mounted and I see hardly any interruption in service using Outlook 2007. Server A shows "Service down", then "Failed" then "Healthy" and leaves the DB mounted on Server B. This is how it should work, so far so good. Now if I test Server A being shut down cold, or unplugging both nics from network to simulate failure, Server B switches from Healthy to Mounted and server A switches to "Service Down" but my outlook client never connects to the DB mounted on server B! I can connect to server C (client access/hub transport) and get to my email and even send new email out, but incoming email doesn't deliver until Server A is brought back online and it's DB goes back to Healthy status. So I don't understand why it auto fail-overs when I reboot the server with the mounted DB copy, causing very little outlook 2007 hiccup if any. But when I shutdown or DC the mounted DB server it DOES mount the healthy copy but outlook 2007 clients can't connect.. I hope the picture I'm trying to paint makes some sense, it's driving me a little batty. Any help would be appreciated!

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• Unexpected start of already-primary server processes when heartbeat on secondary is stopped.

  - by vorik

  Hi, I've got an active-passive Heartbeat cluster with Apache, MySQL, ActiveMQ and DRBD. Today, I wanted to perform hardware-maintenance on the secondary node (node04), so I stopped the heartbeat service before shutting it down. Then, the primary node (node03) received a shutdown notice from the secondary node (node04). This logging comes from the primary node: node03 heartbeat[4458]: 2010/03/08_08:52:56 info: Received shutdown notice from 'node04.companydomain.nl'. heartbeat[4458]: 2010/03/08_08:52:56 info: Resources being acquired from node04.companydomain.nl. harc[27522]: 2010/03/08_08:52:56 info: Running /etc/ha.d/rc.d/status status heartbeat[27523]: 2010/03/08_08:52:56 info: Local Resource acquisition completed. mach_down[27567]: 2010/03/08_08:52:56 info: /usr/share/heartbeat/mach_down: nice_failback: foreign resources acquired mach_down[27567]: 2010/03/08_08:52:56 info: mach_down takeover complete for node node04.companydomain.nl. heartbeat[4458]: 2010/03/08_08:52:56 info: mach_down takeover complete. harc[27620]: 2010/03/08_08:52:56 info: Running /etc/ha.d/rc.d/ip-request-resp ip-request-resp ip-request-resp[27620]: 2010/03/08_08:52:56 received ip-request-resp drbddisk OK yes ResourceManager[27645]: 2010/03/08_08:52:56 info: Acquiring resource group: node03.companydomain.nl drbddisk Filesystem::/dev/drbd0::/data::ext3 mysql apache::/etc/httpd/conf/httpd.conf LVSSyncDaemonSwap::master monitor activemq tivoli-cluster MailTo::[email protected]::DRBDFailureDrisAcc MailTo::[email protected]::DRBDFailureDrisAcc 1.2.3.212 ResourceManager[27645]: 2010/03/08_08:52:56 info: Running /etc/ha.d/resource.d/drbddisk start Filesystem[27700]: 2010/03/08_08:52:57 INFO: Running OK ResourceManager[27645]: 2010/03/08_08:52:57 info: Running /etc/ha.d/resource.d/mysql start mysql[27783]: 2010/03/08_08:52:57 Starting MySQL[ OK ] apache[27853]: 2010/03/08_08:52:57 INFO: Running OK ResourceManager[27645]: 2010/03/08_08:52:57 info: Running /etc/ha.d/resource.d/monitor start monitor[28160]: 2010/03/08_08:52:58 ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/activemq start activemq[28210]: 2010/03/08_08:52:58 Starting ActiveMQ Broker... ActiveMQ Broker is already running. ResourceManager[27645]: 2010/03/08_08:52:58 ERROR: Return code 1 from /etc/ha.d/resource.d/activemq ResourceManager[27645]: 2010/03/08_08:52:58 CRIT: Giving up resources due to failure of activemq ResourceManager[27645]: 2010/03/08_08:52:58 info: Releasing resource group: node03.companydomain.nl drbddisk Filesystem::/dev/drbd0::/data::ext3 mysql apache::/etc/httpd/conf/httpd.conf LVSSyncDaemonSwap::master monitor activemq tivoli-cluster MailTo::[email protected]::DRBDFailureDrisAcc MailTo::[email protected]::DRBDFailureDrisAcc 1.2.3.212 ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/IPaddr 1.2.3.212 stop IPaddr[28329]: 2010/03/08_08:52:58 INFO: ifconfig eth0:0 down IPaddr[28312]: 2010/03/08_08:52:58 INFO: Success ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/MailTo [email protected] DRBDFailureDrisAcc stop MailTo[28378]: 2010/03/08_08:52:58 INFO: Success ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/MailTo [email protected] DRBDFailureDrisAcc stop MailTo[28433]: 2010/03/08_08:52:58 INFO: Success ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/tivoli-cluster stop ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/activemq stop activemq[28503]: 2010/03/08_08:53:01 Stopping ActiveMQ Broker... Stopped ActiveMQ Broker. ResourceManager[27645]: 2010/03/08_08:53:01 info: Running /etc/ha.d/resource.d/monitor stop monitor[28681]: 2010/03/08_08:53:01 ResourceManager[27645]: 2010/03/08_08:53:01 info: Running /etc/ha.d/resource.d/LVSSyncDaemonSwap master stop LVSSyncDaemonSwap[28714]: 2010/03/08_08:53:02 info: ipvs_syncmaster down LVSSyncDaemonSwap[28714]: 2010/03/08_08:53:02 info: ipvs_syncbackup up LVSSyncDaemonSwap[28714]: 2010/03/08_08:53:02 info: ipvs_syncmaster released ResourceManager[27645]: 2010/03/08_08:53:02 info: Running /etc/ha.d/resource.d/apache /etc/httpd/conf/httpd.conf stop apache[28782]: 2010/03/08_08:53:03 INFO: Killing apache PID 18390 apache[28782]: 2010/03/08_08:53:03 INFO: apache stopped. apache[28771]: 2010/03/08_08:53:03 INFO: Success ResourceManager[27645]: 2010/03/08_08:53:03 info: Running /etc/ha.d/resource.d/mysql stop mysql[28851]: 2010/03/08_08:53:24 Shutting down MySQL.....................[ OK ] ResourceManager[27645]: 2010/03/08_08:53:24 info: Running /etc/ha.d/resource.d/Filesystem /dev/drbd0 /data ext3 stop Filesystem[29010]: 2010/03/08_08:53:25 INFO: Running stop for /dev/drbd0 on /data Filesystem[29010]: 2010/03/08_08:53:25 INFO: Trying to unmount /data Filesystem[29010]: 2010/03/08_08:53:25 ERROR: Couldn't unmount /data; trying cleanup with SIGTERM Filesystem[29010]: 2010/03/08_08:53:25 INFO: Some processes on /data were signalled Filesystem[29010]: 2010/03/08_08:53:27 INFO: unmounted /data successfully Filesystem[28999]: 2010/03/08_08:53:27 INFO: Success ResourceManager[27645]: 2010/03/08_08:53:27 info: Running /etc/ha.d/resource.d/drbddisk stop heartbeat[4458]: 2010/03/08_08:53:29 WARN: node node04.companydomain.nl: is dead heartbeat[4458]: 2010/03/08_08:53:29 info: Dead node node04.companydomain.nl gave up resources. heartbeat[4458]: 2010/03/08_08:53:29 info: Link node04.companydomain.nl:eth0 dead. heartbeat[4458]: 2010/03/08_08:53:29 info: Link node04.companydomain.nl:eth1 dead. hb_standby[29193]: 2010/03/08_08:53:57 Going standby [foreign]. heartbeat[4458]: 2010/03/08_08:53:57 info: node03.companydomain.nl wants to go standby [foreign] Soo... What just happened here??? Heartbeat on node04 stopped and told node03, which was the active node at the time. Somehow, node03 decided to start the cluster processes that were already running. (For the processes that are not critical, I always return a 0 from the startupscript so it does not stops the entire cluster when a non-essential part fails.) When starting ActiveMQ, it returns status 1 because it is already running. This fails the node and shuts everything down. As heartbeat is not running on the secondary node, it cannot failover to there. When I tried to run ha_takeover to restart the resources, absolutely nothing happened. Only after I restarted heartbeat on the primary node the resources could be started (after a delay of 2 minutes). These are my questions: Why does heartbeat on the primary node try to start the cluster processes again? Why did ha_takeover not work? What can I do to prevent this from happening? Server configuration: DRBD: version: 8.3.7 (api:88/proto:86-91) GIT-hash: ea9e28dbff98e331a62bcbcc63a6135808fe2917 build by [email protected], 2010-01-20 09:14:48 0: cs:Connected ro:Secondary/Primary ds:UpToDate/UpToDate B r---- ns:0 nr:6459432 dw:6459432 dr:0 al:0 bm:301 lo:0 pe:0 ua:0 ap:0 ep:1 wo:d oos:0 uname -a Linux node04 2.6.18-164.11.1.el5 #1 SMP Wed Jan 6 13:26:04 EST 2010 x86_64 x86_64 x86_64 GNU/Linux haresources node03.companydomain.nl \ drbddisk \ Filesystem::/dev/drbd0::/data::ext3 \ mysql \ apache::/etc/httpd/conf/httpd.conf \ LVSSyncDaemonSwap::master \ monitor \ activemq \ tivoli-cluster \ MailTo::[email protected]::DRBDFailureDrisAcc \ MailTo::[email protected]::DRBDFailureDrisAcc \ 1.2.3.212 ha.cf debugfile /var/log/ha-debug logfile /var/log/ha-log keepalive 500ms deadtime 30 warntime 10 initdead 120 udpport 694 mcast eth0 225.0.0.3 694 1 0 mcast eth1 225.0.0.4 694 1 0 auto_failback off node node03.companydomain.nl node node04.companydomain.nl respawn hacluster /usr/lib64/heartbeat/dopd apiauth dopd gid=haclient uid=hacluster Thank you very much in advance, Ger Apeldoorn

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• Managing scalability and availability with two servers running Apache Httpd, Apache Mina and MySQL

  - by celalo

  Hello, I am not a developer and I don't much experience with scalable server architectures. But I am in need of a highly available and scalable system for one of my projects. There is going to be two servers I am going to use for the time being. Both with 4 core CPUs and 8 GB RAM with RAID structures running CentOS 5.4. I will also have feature called "Failover IP" which enables to direct an IP address to another server within short time. The applications which will be run on the servers: There is going to be a Java application based on Apache Mina server for handling TCP requests from some hundreds of network devices where the devices are going to send request as much as one request per minute. Handling those requests, includes parsing the requests and inserting a few rows to the Database. Parsing requests before inserting data to the DB does take neglectable time. There is going to be MySQL server, as I stated above. Also there is going to be a PHP web application running on Apache Httpd Server which uses the same DB with the Java application. What I wish to have is to make use of those two servers at the most. I was imagining to have the servers identical, sharing the work load. MySQL could be a cluster maybe? And if some application fails or the whole machine goes down, the other will continue serving the requests seamlessly. Reminding that a "Failover IP" feature will be available for me to take advantage of. Also, It should be kept in mind that number of servers could increase in time, to meet the demand. What can you suggest? Which kind of tools I can make use of? Which kind of monitoring software (paid/unpaid) I have? Thanks in advance.

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• What is the difference between Anycast and GeoDNS / GeoIP wrt HA?

  - by Riyad

  Based on the Wikipedia description of Anycast, it includes both the distribution of a domain-name-to-many-IP-mapping across many DNS servers as well as replying to clients with the most geographically close (or fastest) server. In the context of a globally distributed, highly available site like google.com (or any CDN service with many global edge locations) this sounds like the two key features one would need. DNS services like Amazon's Route53, EasyDNS and DNSMadeEasy all advertise themselves as Anycast-enabled networks. Therefore my assumption is that each of these DNS services transparently offer me those two killer features: multi-IP-to-domain mapping AND routing clients to the closest node. However, each of these services seem to separate out these two functionalities, referring to the 2nd one (routing clients to closest node) as "GeoDNS", "GeoIP" or "Global Traffic Director" and charge extra for the service. If a core tenant of an Anycast-capable system is to already do this, why is this functionality being earmarked as this extra feature? What is this "GeoDNS" feature doing that a standard Anycast DNS service won't do (according to the definition of Anycast from Wikipedia -- I understand what is being advertised, just not why it isn't implied already). I get extra-confused when a DNS service like Route53 that doesn't support this nebulous "GeoDNS" feature lists functionality like: Fast – Using a global anycast network of DNS servers around the world, Route 53 is designed to automatically route your users to the optimal location depending on network conditions. As a result, the service offers low query latency for your end users, as well as low update latency for your DNS record management needs. ... which sounds exactly like what GeoDNS is intended to do, but geographically directing clients is something they explicitly don't support it yet. Ultimately I am looking for the two following features from a DNS provider: Map multiple IP addresses to a single domain name (like google.com, amazon.com, etc. does) Utilize a DNS service that will respond to client requests for that domain with the IP address of the nearest server to the requestee. As mentioned, it seems like this is all part of an "Anycast" DNS service (all of which these services are), but the features and marketing I see from them suggest otherwise, making me think I need to learn a bit more about how DNS works before making a deployment choice. Thanks in advance for any clarifications.

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• HAProxy -- pause/queue all traffic without losing requests

  - by Marc

  I basically have the same problem as mentioned in this thread -- I would like to temporarily suspend all requests to all servers of a certain backend, so that I can upgrade the backend and the database it uses. Since this is a live system, I would like to queue up requests, and send them to the backend servers once they've been upgraded. Since I'm doing a database upgrade with the code change, I have to upgrade all backend servers simultaneously, so I can't just bring one down at a time. I tried using the tcp-request options combined with removing the static healthcheck file as mentioned in that thread, but had no luck. Setting the default "maxconn" value to 0 seems to pause and queue connections as desired, but then there seems to be no way to increase the value back to a positive number without restarting HAProxy, which kills all requests that had been queued up until that point. (The "hot-reconfiguration" options using -sf and -st start a new process, which doesn't seem to do what I want). Is what I'm trying to do possible?

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• NFS v4, HA Migration, and stale handles on clients

  - by Karl Katzke

  I'm managing a server running NFS v4 with Pacemaker/OpenAIS. NFS is configured to use TCP. When I migrate the NFS server to another node in the Pacemaker cluster, even though the metadata is persisted, connections from the clients 'hang' and eventually time out after 90 seconds. After that 90 seconds, the old mountpoint becomes 'stale' and the mounted files can no longer be accessed. The 90 second grace period seems to be part of the server configuration and not the client configuration. I see this message on the server: kernel: NFSD: starting 90-second grace period If I restart the NFS client on the client nodes after I migrate (unmounting and then remounting the share), then I don't experience the problem, but connections and file transfers still interrupted. Three questions: What is the 90 second grace period? What's it there for? How can I keep the files from going stale on the clients without restarting them after I migrate the NFS server to another node? Is it actually possible to migrate the NFS server without having large file uploads drop?

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• Software for failover across multiple external hosts

  - by Lin

  I have multiple webservers with the same content, hosted across different providers. However, I can't seem to find a nice, simple failover solution. Load-balancing software (Pound, HAProxy, etc.) are unnecessary, and I need the flexibility to manage over 100+ domains, so the paid DNS failover solutions I've found are too expensive. So far the simplest solution I've thought of is just to set a very low TTL (30min - 1hr) in each zone entry on my nameservers (running BIND). Then, continuously monitor each server, and temporarily remove failed servers from zone entries. But this seems like something that should be currently available. I only have root access to different VPSes running CentOS. Any suggestions? Thanks!

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• Biztalk 2009 logshipping with SQL 2008

  - by Manjot

  Hi, I am setting up biztalk logshipping for Biztalk 2009 database. Following http://msdn.microsoft.com/en-us/library/aa560961.aspx article, I am doing the following to setup biztalk logshipping on destination server: Enable Ad-hoc queries by: sp_configure 'show advanced options',1 go reconfigure go sp_configure 'Ad Hoc Distributed Queries',1 go reconfigure go sp_configure 'show advanced options',0 go reconfigure go Execute LogShipping_Destination_Schema & LogShipping_Destination_Logic in master on destinations server Run: exec bts_ConfigureBizTalkLogShipping @nvcDescription = '', @nvcMgmtDatabaseName = '', @nvcMgmtServerName = '', @SourceServerName = null, -- null indicates that this destination server restores all databases @fLinkServers = 1 -- 1 automatically links the server to the management database When I run this I am receiving the following error: Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'. After some research I found some info : Usually this error means that the SQL Server Service Principal Name (SPN) was not configured, and NTLM was not being used as an authentication mechanism. SQl services are runing under different domain accounts. So, I asked the domain admin to create SPNs for the servers, SQL service accounts for beoth source and destination using name and FQDN. enabled computer name and service accounts for delegation. When I run the following: select * from sys.dm_exec_connections I get the the same error: Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON' Any help please?

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• Server Configuration / Important Parameter for 500Req/Second

  - by Sparsh Gupta

  I am configuring a server to be used as nginx server for a very heavy traffic website. It is expected to receive traffic from a large number of IP addresses simultaneously. It is expected to get 500Req/Second with atleast 20Million unique IPs connecting it. One of the problems I noticed in my previos server was related to iptables / ipconntrack. I am not aware of this behaviour and would be glad to know which all parameters of a ubuntu / debian (32/64) bit machine should I tweek to get maximum performance from the server. I can put in a lot of RAM on the server but mission critical task is the response times. We ideally dont want any connection to be hanging / timing out / waiting and want as low as possible overall response times. P.S. We are also looking for a kick ass freelancer system admin who can help us figuring / setting this all up. Reach me incase you have some spare time and interested in working on some very heavy traffic website servers.

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• HD Video Capture Card w/ Good API?

  - by Sheep Slapper

  Does anyone here know of a good HD video capture card that has a good (comprehensive) API? I administer a few servers that do some video encoding right now, but when we make the switch to HD cameras, they won't be sufficient. In addition to this, the servers we have now are black boxes, closed to me except to start/stop the video capture device. I'd like to be able to roll my own, so we can better integrate it with our existing systems, but I know almost nothing about what kind of HD capture cards are out there, and if I can avoid spending money just to test their APIs that would rock. So does anyone have any experience with this? All our other software is in C#, and I'd like to set up the new servers with web interfaces to start/stop the capture (also in C#, using .NET 3.5 probably). I'm not sure how language specific these APIs would be, but that's what I'm working with just as a reference point. I appreciate any help the community can give!

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• How do I replace the screen of a Dell Ispiron 1545?

  - by Ajus10

  I got a new screen for a Dell Inspiron 1545. The old screen says Dell Inspiron 1545 LP156WH1 (TL)(C1?) HD and the new one says Dell Inspiron 1545 LP156WH1 (TL)(C1?) LCD Does that make a difference? All I can get to work on the new screen is the backlight. The old screen had a crack. Now when I plug the old one in, it will not turn on at all. Could I have blown the inverter or messed up the cable?

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• Free video conversion software that supports widescreen format

  - by Brian Kim

  Is there a good video conversion software for Windows that supports widescreen format? Things I tried from download.com don't support widescreen. It creates black bars top and bottom. I like AVS Video Converter, but it isn't free. Is there a good free one?

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• MySQL: Pacemaker cannot start the failed master as a new slave?

  - by quanta

  I'm going to setup failover for MySQL replication (1 master and 1 slave) follow this guide: https://github.com/jayjanssen/Percona-Pacemaker-Resource-Agents/blob/master/doc/PRM-setup-guide.rst Here're the output of crm configure show: node serving-6192 \ attributes p_mysql_mysql_master_IP="192.168.6.192" node svr184R-638.localdomain \ attributes p_mysql_mysql_master_IP="192.168.6.38" primitive p_mysql ocf:percona:mysql \ params config="/etc/my.cnf" pid="/var/run/mysqld/mysqld.pid" socket="/var/lib/mysql/mysql.sock" replication_user="repl" replication_passwd="x" test_user="test_user" test_passwd="x" \ op monitor interval="5s" role="Master" OCF_CHECK_LEVEL="1" \ op monitor interval="2s" role="Slave" timeout="30s" OCF_CHECK_LEVEL="1" \ op start interval="0" timeout="120s" \ op stop interval="0" timeout="120s" primitive writer_vip ocf:heartbeat:IPaddr2 \ params ip="192.168.6.8" cidr_netmask="32" \ op monitor interval="10s" \ meta is-managed="true" ms ms_MySQL p_mysql \ meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true" globally-unique="false" target-role="Master" is-managed="true" colocation writer_vip_on_master inf: writer_vip ms_MySQL:Master order ms_MySQL_promote_before_vip inf: ms_MySQL:promote writer_vip:start property $id="cib-bootstrap-options" \ dc-version="1.0.12-unknown" \ cluster-infrastructure="openais" \ expected-quorum-votes="2" \ no-quorum-policy="ignore" \ stonith-enabled="false" \ last-lrm-refresh="1341801689" property $id="mysql_replication" \ p_mysql_REPL_INFO="192.168.6.192|mysql-bin.000006|338" crm_mon: Last updated: Mon Jul 9 10:30:01 2012 Stack: openais Current DC: serving-6192 - partition with quorum Version: 1.0.12-unknown 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ serving-6192 svr184R-638.localdomain ] Master/Slave Set: ms_MySQL Masters: [ serving-6192 ] Slaves: [ svr184R-638.localdomain ] writer_vip (ocf::heartbeat:IPaddr2): Started serving-6192 Editing /etc/my.cnf on the serving-6192 of wrong syntax to test failover and it's working fine: svr184R-638.localdomain being promoted to become the master writer_vip switch to svr184R-638.localdomain Current state: Last updated: Mon Jul 9 10:35:57 2012 Stack: openais Current DC: serving-6192 - partition with quorum Version: 1.0.12-unknown 2 Nodes configured, 2 expected votes 2 Resources configured. ============ Online: [ serving-6192 svr184R-638.localdomain ] Master/Slave Set: ms_MySQL Masters: [ svr184R-638.localdomain ] Stopped: [ p_mysql:0 ] writer_vip (ocf::heartbeat:IPaddr2): Started svr184R-638.localdomain Failed actions: p_mysql:0_monitor_5000 (node=serving-6192, call=15, rc=7, status=complete): not running p_mysql:0_demote_0 (node=serving-6192, call=22, rc=7, status=complete): not running p_mysql:0_start_0 (node=serving-6192, call=26, rc=-2, status=Timed Out): unknown exec error Remove the wrong syntax from /etc/my.cnf on serving-6192, and restart corosync, what I would like to see is serving-6192 was started as a new slave but it doesn't: Failed actions: p_mysql:0_start_0 (node=serving-6192, call=4, rc=1, status=complete): unknown error Here're snippet of the logs which I'm suspecting: Jul 09 10:46:32 serving-6192 lrmd: [7321]: info: rsc:p_mysql:0:4: start Jul 09 10:46:32 serving-6192 lrmd: [7321]: info: RA output: (p_mysql:0:start:stderr) Error performing operation: The object/attribute does not exist Jul 09 10:46:32 serving-6192 crm_attribute: [7420]: info: Invoked: /usr/sbin/crm_attribute -N serving-6192 -l reboot --name readable -v 0 The full logs: http://fpaste.org/AyOZ/ The strange thing is I can starting it manually: export OCF_ROOT=/usr/lib/ocf export OCF_RESKEY_config="/etc/my.cnf" export OCF_RESKEY_pid="/var/run/mysqld/mysqld.pid" export OCF_RESKEY_socket="/var/lib/mysql/mysql.sock" export OCF_RESKEY_replication_user="repl" export OCF_RESKEY_replication_passwd="x" export OCF_RESKEY_test_user="test_user" export OCF_RESKEY_test_passwd="x" sh -x /usr/lib/ocf/resource.d/percona/mysql start: http://fpaste.org/RVGh/ Did I make something wrong?

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• What's the difference between keepalived and corosync, others?

  - by Matt

  I'm building a failover firewall for a server cluster and started looking at the various options. I'm more familiar with carp on freebsd, but need to use linux for this project. Searching google has produced several different projects, but no clear information about features they provide . CARP gave virtual interfaces that failover, I am not really clear on whether that's what corosync does, or is that what pacemaker does? On the other hand I did get manage to get keepalived working. However, I noted that corosync provides native support for infiniband. This would be useful for me. Perhaps someone could shed some light on the differences between: corosync keepalive pacemaker heartbeat Which product would be the best fit for router failover?

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• PSU requirement question for my PC setup.

  - by user69474

  I understand that sometimes there may be a situation where the PSU is way more than required but in this case of mine, I'm not too sure. Sometimes when I play games, my computer will crash and restarts itself, 10 mins into the game. Once I received a message that says something like the power is overheating or something like that. Ok, so I have a 500W PSU. I have: 1x Internal DVD writer 1x SATA 250GB HD 1x Nvidia 8500 GT 2GB RAM. As I'm planning to get an additional 250GB SATA HD, I wonder if I need to increase my PSU as well -- in full knowledge of the previous crashes experienced before. Should I upgrade my PSU to 650W perhaps, or is that excessive?

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