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  • How to preseed 12.10 desktop when the ubuntu-desktop package is missing?

    - by user183394
    I have been trying to use a preseed file to do PXE booting of a 12.10 desktop. Upon the first boot, I was greeted by a terminal with login prompt. Surprised, I checked the /var/log/installer/syslog but didn't find a trace of desktop installation. Feeling curious, I double-checked the content of the loop mounted iso file, and realized that the ubuntu-desktop package that existed up to 12.04.1 is no longer available. So, the following preseed lines from the Ubuntu preseed example no longer apply: ################################################################################ ### Package selection ### ################################################################################ # Selected packages. tasksel tasksel/first multiselect ubuntu-desktop #tasksel tasksel/first multiselect lamp-server, print-server #tasksel tasksel/first multiselect kubuntu-desktop Given such a situation, is there something that I can specify in the pre-seed file to install the entire default desktop?

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  • Fails to boot after upgrade, stuck on winbind package

    - by Praetorian
    I started the upgrade from 11.04 to 11.10 last night. Once it got the installing packages part I left the computer unattended the rest of the night. When I checked it this morning the screen was blank and I couldn't get it to turn on. So I cycled power, and now I get the "Ubuntu 11.10" screen with the dots underneath, but then it gets to a blank screen and nothing more. I can get to the command line in recovery mode; here's a list of the things I've tried so far sudo apt-get update - the very first repository it checked sat at 0% for a long time (network cable is plugged in), so I cancelled with Ctrl+C Thought it might be a problem with display drivers, so I tried sudo apt-get install nvidia-glx - this gave me an error saying dpkg has been interrupted, manually run sudo dpkg --configure -a sudo dpkg --configure -a this installed / updated a bunch of stuff but got stuck at Starting Winbind daemon winbind Restarted and tried sudo dpkg --configure -a again but it gets stuck at same Windbind step What else can I do to fix this problem?

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  • Where are bluetooth received files saved

    - by Luis Alvarado
    I have used Blueman and the default Bluetooth manager an every time I accept the file transfer from the Phone to the PC, it shows that it is transferring and even notifies me that the transfer was successful but I can not find the image anywhere. Where are files stored after sending them via Bluetooth to the PC? I already checked my Home folder. The Picture folder which I thought it would be the one for images. Then the document folder and afterwards I did a huge check on all folders under /home. No luck. Is nowhere. I even checked this answer with no luck.

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  • How would you gather client's data on Google App Engine without using Datastore/Backend Instances too much?

    - by ruslan
    I'm relatively new to StackExchange and not sure if it's appropriate place to ask design question. Site gives me a hint "The question you're asking appears subjective and is likely to be closed". Please let me know. Anyway.. One of the projects I'm working on is online survey engine. It's my first big commercial project on Google App Engine. I need your advice on how to collect stats and efficiently record them in DataStore without bankrupting me. Initial requirements are: After user finishes survey client sends list of pairs [ID (int) + PercentHit (double)]. This list shows how close answers of this user match predefined answers of reference answerers (which identified by IDs). I call them "target IDs". Creator of the survey wants to see aggregated % for given IDs for last hour, particular timeframe or from the beginning of the survey. Some surveys may have thousands of target/reference answerers. So I created entity public class HitsStatsDO implements Serializable { @Id transient private Long id; transient private Long version = (long) 0; transient private Long startDate; @Parent transient private Key parent; // fake parent which contains target id @Transient int targetId; private double avgPercent; private long hitCount; } But writing HitsStatsDO for each target from each user would give a lot of data. For instance I had a survey with 3000 targets which was answered by ~4 million people within one week with 300K people taking survey in first day. Even if we assume they were answering it evenly for 24 hours it would give us ~1040 writes/second. Obviously it hits concurrent writes limit of Datastore. I decided I'll collect data for one hour and save that, that's why there are avgPercent and hitCount in HitsStatsDO. GAE instances are stateless so I had to use dynamic backend instance. There I have something like this: // Contains stats for one hour private class Shard { ReadWriteLock lock = new ReentrantReadWriteLock(); Map<Integer, HitsStatsDO> map = new HashMap<Integer, HitsStatsDO>(); // Key is target ID public void saveToDatastore(); public void updateStats(Long startDate, Map<Integer, Double> hits); } and map with shard for current hour and previous hour (which doesn't stay here for long) private HashMap<Long, Shard> shards = new HashMap<Long, Shard>(); // Key is HitsStatsDO.startDate So once per hour I dump Shard for previous hour to Datastore. Plus I have class LifetimeStats which keeps Map<Integer, HitsStatsDO> in memcached where map-key is target ID. Also in my backend shutdown hook method I dump stats for unfinished hour to Datastore. There is only one major issue here - I have only ONE backend instance :) It raises following questions on which I'd like to hear your opinion: Can I do this without using backend instance ? What if one instance is not enough ? How can I split data between multiple dynamic backend instances? It hard because I don't know how many I have because Google creates new one as load increases. I know I can launch exact number of resident backend instances. But how many ? 2, 5, 10 ? What if I have no load at all for a week. Constantly running 10 backend instances is too expensive. What do I do with data from clients while backend instance is dead/restarting? Thank you very much in advance for your thoughts.

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  • Why is Google Webmaster Tools crawling invalid URLS and showing 500 errors?

    - by Amos Kane
    Google Webmaster tools is reporting 12k+ 500 errors. Eeek! None of the URLS are valid- they all contain www.youtube.com. First, why is Google crawling these URLS if they don't exist? I supplied a sitemap, and they are of course not in the sitemap. I don't have a robots.txt blocking anything. I've checked for invalid redirects--none, and checked for unclosed tags or something that would throw www.youtube.com into the URL by accident--none. In every 'linked from', the referring URL is also a bad URL, with www.youtube.com in it. The Google Tools report no malware, and I can't check the server logs because the host won't give me access. Really stuck!! Any ideas appreciated!

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  • Why google is not crawling my website

    - by Aman Virk
    I am running a design and development blog http://www.thetutlage.com/ . From last couple of days my search traffic have been reduced from 70% to 10%. I myself is against black hat seo and all it do is write my own unique content almost everyday. Last week my search traffic was really good but now is dropping like heck. I have checked my webmasters dashboard and no message there from google. When i checked server logs i came to know last time google crawled my website was on 27 september 2012. Really i have no idea what i am doing wrong. I follow all google guidelines like bible, please help me

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  • How can I remove packages using preseed?

    - by Jorge Castro
    I'm setting up an automated "no questions asked" preseed system and using Dustin Kirkland's server preseed as an example. He uses the following line to install three packages as part of the automated install: d-i pkgsel/include string byobu vim openssh-server I am looking for the inverse of this, basically be able to remove packages as part of the automated install. I've checked the Installation Guide I've checked this example preseed, but it's not clear if this is the canonical list of every single option available. I am thinking I need to to use d-i preseed/late_command string apt-remove packagename to clean up stuff I don't want when the install is done, but I am not sure

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  • How to find the exact font used by the browser

    - by sreekanth
    I have used the css style sheet as font-family:arial,helvicta,sans-serif,etc... in a php file when i checked it in browser i dont know which font it is using from the font-family . i wanted to know the exact font used by the browser to display. i.e whether it is using arial or helvicta or sans-serif for the text i have displayed. please any one let me know to find this. i have checked by putting this in wordpad but it is taking my default system font. Thanks in advance

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  • Managing BES Software Configurations

    - by DaveJohnston
    Hi, I am having problems with OTA deployment of a bespoke application that we have written. I have read loads of threads elsewhere and I have got mixed help, but for my particular case none of it has really helped. So I thought I would explain my exact situation and try and get some help here. I am running BES version 4.1.5 (Bundle 79) for Microsoft Exchange. The application we have written is split into 5 modules, which we control, and another 4 modules which are 3rd party libraries that we require. So for our modules the version numbers are regularly changing but for the others they are pretty much always going to remain the same. We have an alx file set up that identifies all of the files required and in fact I am able to create a software configuration and deploy the application with no problems. What I am trying to do however is maintain multiple versions of our application on the BES and be able to select which version I want to deploy to each user. I have tried this a number of ways (as I said I have read lots of other threads with solutions to this problem) but each seems to come with its own problem. First of all I tried just creating different configurations for each version of the application, but because they each had the same application ID the BES informed me that I couldn't do this. I read somewhere that the solution was to create a second shared folder (e.g. \Program Files\Common Files\RIM) and add the apploader stuff and the new version of the app to this folder. I could then create a second software configuration that would have the same application ID. The result of this seemed promising to start with. When I changed the config that was assigned to a user the new version was pushed out fine. But afterwards the BES reported that the device state was invalid, which meant I couldn't push anything else until I reactivated the device. I guess this is because the first config was never set to disallowed so the old version wasn't removed and the device essentially reported that it had multiple versions of the same application installed. The next suggestion I got was to change the application ID for each version, e.g. to include the version number. This meant that each version of the application could be included in a single configuration and I could set one to disallowed and the other to required. Initially this worked and the first version was deployed. But when I switched (i.e. the old version became disallowed and the new version required) the BES reported upgrade required and removed the old version. The device restarts and the old version is gone but the new version is not pushed out. I checked the BES and it still said Upgrade Required. I checked the log files and found: [40000] (11/12 09:50:27.397):{0xEB8} {[email protected], PIN=1234, UserId=2}SCS::PollDBQueueNewRequests - Queuing POLL_FOR_MISSING_APPS request [40000] (11/12 09:50:28.241):{0xE9C} RequestHandler::PollForMissingApps: Starting Poll For Missing Apps. [40304] (11/12 09:50:28.241):{0xE90} WorkerThreadPool:: ThreadProc(): Thread released with empty queue [40000] (11/12 09:50:28.241):{0xE9C} SCS::RemoveAppDeliveryRequests - No App Delivery Requests purged for User id 2 [30000] (11/12 09:50:28.960):{0xE9C} Discard duplicate module group "name" on device [30000] (11/12 09:50:28.960):{0xE9C} Discard duplicate module group "name" on device [40000] (11/12 09:50:29.163):{0xE9C} RequestHandler::PollForMissingApps: Completed Poll For Missing Apps, elapsed time 0.922 seconds. (You will notice I have removed actual names and email addresses etc for privacy reasons. But one question: where does the name of the module group come from? In my case it is close to the application ID but doesn't include the version number that I added at the end in order to get it to work. Is that information embedded in a COD file or something??) So it is reporting a duplicate module group on the device? What does this mean? I checked the device properties (as reported on the BES) and it confirms that the modules with the old version numbers are still present on the device. So the application has been removed but not the modules?? I checked the device and the modules are gone, so it is just the BES reporting that they are still there?? I checked the database and it has the modules in questions in the SyncDeviceMgmt table. If I delete these from the DB the BES changes to report Install Required, and low and behold the new version of the app is pushed out. So at the end of all that, my question is: does anyone have any other suggestions of how to handle upgrading our bespoke application OTA from the BES? Or can anyone point out something I am doing wrong in what I described above that might solve the problems I am having? I guess the question is why does the database maintain that the modules are on the device after they are removed? Thanks for any help you can provide.

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  • how to bind data binding source to group radio buttons

    Hi I am working on windows c# application (visual studio 20008).In my form I have 5 Radio buttons ,grouped by group box. I have to bind this radio button to data binding source. this.rdoptPlus.DataBindings.Add(new Binding("Checked", MemberDefinitionsBindingSource, "UnaryOperator", true)); this.rdoptMinus.DataBindings.Add(new Binding("Checked", MemberDefinitionsBindingSource, "UnaryOperator", true)); i am unable to bind single datacolum to 5 radio buttons,please help me  read moreBy masuri suhasiniDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Five Fake Sounds Engineered to Make Your Feel Better [Science]

    - by Jason Fitzpatrick
    As objects in our environment (like cars, ATMs, and phones) have grown lighter and quieter scientists have been carefully engineering their sounds so that they continue to sound like we expect them to. Read on to see how. At the design blog Humans Invent they share five interesting ways that the world around us is being engineered so it sounds the way we expect it to. They start with the example of the car door. Years ago cars were almost entirely steel, the doors were weighty, and when you slammed them it sounded like one big hunk of steel locking into another big hunk of steel (which, in fact, it was). Newer cars are lighter but people still crave that substantial clunk. Humans Invent highlights the effect of consumer desire: A car door is essentially a hollow shell with parts placed inside it. Without careful design the door frame amplifies the rattling of mechanisms inside. Car companies know that if buyers don’t get a satisfying thud when they close the door, it dents their confidence in the entire vehicle. To produce the ideal clunk, car doors are designed to minimise the amount of high frequencies produced (we associate them with fragility and weakness) and emphasise low, bass-heavy frequencies that suggest solidity. The effect is achieved in a range of different ways – car companies have piled up hundreds of patents on the subject – but usually involves some form of dampener fitted in the door cavity. Locking mechanisms are also tailored to produce the right sort of click and the way seals make contact is precisely controlled. On average it takes 1.8 seconds to close a car door but in that time you’re witnessing a strange kind of symphony composed by engineers and designers whose goal is to reassure you that its rock solid. They mention lock mechanisms, something you may never have thought about. A friend of mine had a Ford Focus some years ago and that particular model had electric locks that, instead of giving a satisfying thunk or solid click, made this horrible gates-of-the-prison-buzzing sound that was completely unnerving. Hit up the link below to see how sounds are engineered for car doors, electric motors, ATM machines, and more. 5 Fake Sounds Designed to Help Humans [Humans Invent via Boing Boing] How To Easily Access Your Home Network From Anywhere With DDNSHow To Recover After Your Email Password Is CompromisedHow to Clean Your Filthy Keyboard in the Dishwasher (Without Ruining it)

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  • rotate player based off of joystick

    - by pengume
    Hey everyone I have this game that i am making in android and I have a touch screen joystick that moves the player around based on the joysticks position. I cant figure out how to also get the player to rotate at the same angle of the joystick. so when the joystick is to the left the players bitmap is rotated to the left as well. Maybe someone here has some sample code I could look at here is the joysticks class that I am using. `public class GameControls implements OnTouchListener { public float initx = DroidzActivity.screenWidth - 45; //255; // 320 og 425 public float inity = DroidzActivity.screenHeight - 45;//425; // 480 og 267 public Point _touchingPoint = new Point( DroidzActivity.screenWidth - 45, DroidzActivity.screenHeight - 45); public Point _pointerPosition = new Point(DroidzActivity.screenWidth - 100, DroidzActivity.screenHeight - 100); // ogx 220 ogy 150 private Boolean _dragging = false; private boolean attackMode = false; @Override public boolean onTouch(View v, MotionEvent event) { update(event); return true; } private MotionEvent lastEvent; public boolean ControlDragged; private static double angle; public void update(MotionEvent event) { if (event == null && lastEvent == null) { return; } else if (event == null && lastEvent != null) { event = lastEvent; } else { lastEvent = event; } // drag drop if (event.getAction() == MotionEvent.ACTION_DOWN) { if ((int) event.getX() > 0 && (int) event.getX() < 50 && (int) event.getY() > DroidzActivity.screenHeight - 160 && (int) event.getY() < DroidzActivity.screenHeight - 0) { setAttackMode(true); } else { _dragging = true; } } else if (event.getAction() == MotionEvent.ACTION_UP) { if(isAttackMode()){ setAttackMode(false); } _dragging = false; } if (_dragging) { ControlDragged = true; // get the pos _touchingPoint.x = (int) event.getX(); _touchingPoint.y = (int) event.getY(); // Log.d("GameControls", "x = " + _touchingPoint.x + " y = " //+ _touchingPoint.y); // bound to a box if (_touchingPoint.x < DroidzActivity.screenWidth - 75) { // og 400 _touchingPoint.x = DroidzActivity.screenWidth - 75; } if (_touchingPoint.x > DroidzActivity.screenWidth - 15) {// og 450 _touchingPoint.x = DroidzActivity.screenWidth - 15; } if (_touchingPoint.y < DroidzActivity.screenHeight - 75) {// og 240 _touchingPoint.y = DroidzActivity.screenHeight - 75; } if (_touchingPoint.y > DroidzActivity.screenHeight - 15) {// og 290 _touchingPoint.y = DroidzActivity.screenHeight - 15; } // get the angle setAngle(Math.atan2(_touchingPoint.y - inity, _touchingPoint.x - initx) / (Math.PI / 180)); // Move the ninja in proportion to how far // the joystick is dragged from its center _pointerPosition.y += Math.sin(getAngle() * (Math.PI / 180)) * (_touchingPoint.x / 70); // og 180 70 _pointerPosition.x += Math.cos(getAngle() * (Math.PI / 180)) * (_touchingPoint.x / 70); // make the pointer go thru if (_pointerPosition.x > DroidzActivity.screenWidth) { _pointerPosition.x = 0; } if (_pointerPosition.x < 0) { _pointerPosition.x = DroidzActivity.screenWidth; } if (_pointerPosition.y > DroidzActivity.screenHeight) { _pointerPosition.y = 0; } if (_pointerPosition.y < 0) { _pointerPosition.y = DroidzActivity.screenHeight; } } else if (!_dragging) { ControlDragged = false; // Snap back to center when the joystick is released _touchingPoint.x = (int) initx; _touchingPoint.y = (int) inity; // shaft.alpha = 0; } } public void setAttackMode(boolean attackMode) { this.attackMode = attackMode; } public boolean isAttackMode() { return attackMode; } public void setAngle(double angle) { this.angle = angle; } public static double getAngle() { return angle; } }` I should also note that the player has animations based on when he is moving or attacking.

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  • How can I gather client's data on Google App Engine without using Datastore/Backend Instances too much?

    - by ruslan
    One of the projects I'm working on is online survey engine. It's my first big commercial project on Google App Engine. I need your advice on how to collect stats and efficiently record them in DataStore without bankrupting me. Initial requirements are: After user finishes survey client sends list of pairs [ID (int) + PercentHit (double)]. This list shows how close answers of this user match predefined answers of reference answerers (which identified by IDs). I call them "target IDs". Creator of the survey wants to see aggregated % for given IDs for last hour, particular timeframe or from the beginning of the survey. Some surveys may have thousands of target/reference answerers. So I created entity public class HitsStatsDO implements Serializable { @Id transient private Long id; transient private Long version = (long) 0; transient private Long startDate; @Parent transient private Key parent; // fake parent which contains target id @Transient int targetId; private double avgPercent; private long hitCount; } But writing HitsStatsDO for each target from each user would give a lot of data. For instance I had a survey with 3000 targets which was answered by ~4 million people within one week with 300K people taking survey in first day. Even if we assume they were answering it evenly for 24 hours it would give us ~1040 writes/second. Obviously it hits concurrent writes limit of Datastore. I decided I'll collect data for one hour and save that, that's why there are avgPercent and hitCount in HitsStatsDO. GAE instances are stateless so I had to use dynamic backend instance. There I have something like this: // Contains stats for one hour private class Shard { ReadWriteLock lock = new ReentrantReadWriteLock(); Map<Integer, HitsStatsDO> map = new HashMap<Integer, HitsStatsDO>(); // Key is target ID public void saveToDatastore(); public void updateStats(Long startDate, Map<Integer, Double> hits); } and map with shard for current hour and previous hour (which doesn't stay here for long) private HashMap<Long, Shard> shards = new HashMap<Long, Shard>(); // Key is HitsStatsDO.startDate So once per hour I dump Shard for previous hour to Datastore. Plus I have class LifetimeStats which keeps Map<Integer, HitsStatsDO> in memcached where map-key is target ID. Also in my backend shutdown hook method I dump stats for unfinished hour to Datastore. There is only one major issue here - I have only ONE backend instance :) It raises following questions on which I'd like to hear your opinion: Can I do this without using backend instance ? What if one instance is not enough ? How can I split data between multiple dynamic backend instances? It hard because I don't know how many I have because Google creates new one as load increases. I know I can launch exact number of resident backend instances. But how many ? 2, 5, 10 ? What if I have no load at all for a week. Constantly running 10 backend instances is too expensive. What do I do with data from clients while backend instance is dead/restarting?

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  • alt+shift can't be set to toggle language

    - by Ali
    I recently did a fresh installation of Ubuntu 13.10; but there is something bothering me, which I don't quite understand. When I first tried to toggle the keyboard language(I usually switch between Persian and English) using the good old "alt+shift" shortcut it didn't work. Then, I went and checked the Keyboard shortcut settings and found out that it had been set to "super+space"(which BTW didn't work either). So I tried to change it back to "alt+shift" but it just doesn't work; when I press "alt+shift" to set it up as the toggle-language shortcut, the box automatically resets itself to its previous value(without any errors whatsoever). As far as I've checked I couldn't find any thing obvious corresponding to the shortcut "alt+shift" either. I've currently set up the shortcut as "Ctrl+space"; so I can toggle the language. My question is why I cannot set it up to just "alt+shift"?

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  • Online ALTER TABLE in MySQL 5.6

    - by Marko Mäkelä
    This is the low-level view of data dictionary language (DDL) operations in the InnoDB storage engine in MySQL 5.6. John Russell gave a more high-level view in his blog post April 2012 Labs Release – Online DDL Improvements. MySQL before the InnoDB Plugin Traditionally, the MySQL storage engine interface has taken a minimalistic approach to data definition language. The only natively supported operations were CREATE TABLE, DROP TABLE and RENAME TABLE. Consider the following example: CREATE TABLE t(a INT); INSERT INTO t VALUES (1),(2),(3); CREATE INDEX a ON t(a); DROP TABLE t; The CREATE INDEX statement would be executed roughly as follows: CREATE TABLE temp(a INT, INDEX(a)); INSERT INTO temp SELECT * FROM t; RENAME TABLE t TO temp2; RENAME TABLE temp TO t; DROP TABLE temp2; You could imagine that the database could crash when copying all rows from the original table to the new one. For example, it could run out of file space. Then, on restart, InnoDB would roll back the huge INSERT transaction. To fix things a little, a hack was added to ha_innobase::write_row for committing the transaction every 10,000 rows. Still, it was frustrating that even a simple DROP INDEX would make the table unavailable for modifications for a long time. Fast Index Creation in the InnoDB Plugin of MySQL 5.1 MySQL 5.1 introduced a new interface for CREATE INDEX and DROP INDEX. The old table-copying approach can still be forced by SET old_alter_table=0. This interface is used in MySQL 5.5 and in the InnoDB Plugin for MySQL 5.1. Apart from the ability to do a quick DROP INDEX, the main advantage is that InnoDB will execute a merge-sort algorithm before inserting the index records into each index that is being created. This should speed up the insert into the secondary index B-trees and potentially result in a better B-tree fill factor. The 5.1 ALTER TABLE interface was not perfect. For example, DROP FOREIGN KEY still invoked the table copy. Renaming columns could conflict with InnoDB foreign key constraints. Combining ADD KEY and DROP KEY in ALTER TABLE was problematic and not atomic inside the storage engine. The ALTER TABLE interface in MySQL 5.6 The ALTER TABLE storage engine interface was completely rewritten in MySQL 5.6. Instead of introducing a method call for every conceivable operation, MySQL 5.6 introduced a handful of methods, and data structures that keep track of the requested changes. In MySQL 5.6, online ALTER TABLE operation can be requested by specifying LOCK=NONE. Also LOCK=SHARED and LOCK=EXCLUSIVE are available. The old-style table copying can be requested by ALGORITHM=COPY. That one will require at least LOCK=SHARED. From the InnoDB point of view, anything that is possible with LOCK=EXCLUSIVE is also possible with LOCK=SHARED. Most ALGORITHM=INPLACE operations inside InnoDB can be executed online (LOCK=NONE). InnoDB will always require an exclusive table lock in two phases of the operation. The execution phases are tied to a number of methods: handler::check_if_supported_inplace_alter Checks if the storage engine can perform all requested operations, and if so, what kind of locking is needed. handler::prepare_inplace_alter_table InnoDB uses this method to set up the data dictionary cache for upcoming CREATE INDEX operation. We need stubs for the new indexes, so that we can keep track of changes to the table during online index creation. Also, crash recovery would drop any indexes that were incomplete at the time of the crash. handler::inplace_alter_table In InnoDB, this method is used for creating secondary indexes or for rebuilding the table. This is the ‘main’ phase that can be executed online (with concurrent writes to the table). handler::commit_inplace_alter_table This is where the operation is committed or rolled back. Here, InnoDB would drop any indexes, rename any columns, drop or add foreign keys, and finalize a table rebuild or index creation. It would also discard any logs that were set up for online index creation or table rebuild. The prepare and commit phases require an exclusive lock, blocking all access to the table. If MySQL times out while upgrading the table meta-data lock for the commit phase, it will roll back the ALTER TABLE operation. In MySQL 5.6, data definition language operations are still not fully atomic, because the data dictionary is split. Part of it is inside InnoDB data dictionary tables. Part of the information is only available in the *.frm file, which is not covered by any crash recovery log. But, there is a single commit phase inside the storage engine. Online Secondary Index Creation It may occur that an index needs to be created on a new column to speed up queries. But, it may be unacceptable to block modifications on the table while creating the index. It turns out that it is conceptually not so hard to support online index creation. All we need is some more execution phases: Set up a stub for the index, for logging changes. Scan the table for index records. Sort the index records. Bulk load the index records. Apply the logged changes. Replace the stub with the actual index. Threads that modify the table will log the operations to the logs of each index that is being created. Errors, such as log overflow or uniqueness violations, will only be flagged by the ALTER TABLE thread. The log is conceptually similar to the InnoDB change buffer. The bulk load of index records will bypass record locking. We still generate redo log for writing the index pages. It would suffice to log page allocations only, and to flush the index pages from the buffer pool to the file system upon completion. Native ALTER TABLE Starting with MySQL 5.6, InnoDB supports most ALTER TABLE operations natively. The notable exceptions are changes to the column type, ADD FOREIGN KEY except when foreign_key_checks=0, and changes to tables that contain FULLTEXT indexes. The keyword ALGORITHM=INPLACE is somewhat misleading, because certain operations cannot be performed in-place. For example, changing the ROW_FORMAT of a table requires a rebuild. Online operation (LOCK=NONE) is not allowed in the following cases: when adding an AUTO_INCREMENT column, when the table contains FULLTEXT indexes or a hidden FTS_DOC_ID column, or when there are FOREIGN KEY constraints referring to the table, with ON…CASCADE or ON…SET NULL option. The FOREIGN KEY limitations are needed, because MySQL does not acquire meta-data locks on the child or parent tables when executing SQL statements. Theoretically, InnoDB could support operations like ADD COLUMN and DROP COLUMN in-place, by lazily converting the table to a newer format. This would require that the data dictionary keep multiple versions of the table definition. For simplicity, we will copy the entire table, even for DROP COLUMN. The bulk copying of the table will bypass record locking and undo logging. For facilitating online operation, a temporary log will be associated with the clustered index of table. Threads that modify the table will also write the changes to the log. When altering the table, we skip all records that have been marked for deletion. In this way, we can simply discard any undo log records that were not yet purged from the original table. Off-page columns, or BLOBs, are an important consideration. We suspend the purge of delete-marked records if it would free any off-page columns from the old table. This is because the BLOBs can be needed when applying changes from the log. We have special logging for handling the ROLLBACK of an INSERT that inserted new off-page columns. This is because the columns will be freed at rollback.

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  • How does one handle sensitive data when using Github and Heroku?

    - by Jonas
    I am not yet accustomed with the way Git works (And wonder if someone besides Linus is ;)). If you use Heroku to host you application, you need to have your code checked in a Git repo. If you work on an open-source project, you are more likely going to share this repo on Github or other Git hosts. Some things should not be checked in the public repo; database passwords, API keys, certificates, etc... But these things still need to be part of the Git repo since you use it to push your code to Heroku. How to work with this use case? Note: I know that Heroku or PHPFog can use server variables to circumvent this problem. My question is more about how to "hide" parts of the code.

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  • SSIS Denali CTP1 Source Assistant

    - by andyleonard
    I like the new Data Flow Source Assistant in SSIS Denali. The default view is shown above, with the "Show installed only" checkbox checked. When not checked, the list of Source types changes: In previous versions of SSIS, I rarely created connections in the Connection Managers pane - I usually hit a New button in either a Source or Destination Adapter, or in a task. It was just easier letting the task or adapter pick the proper Connection Manager editor. This is handy and a time-saver. :{>...(read more)

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  • Frequent GUI pauses in Ubuntu 13.04 / Unity / Intel HD4000

    - by Simon
    I'm experiencing very frequent (and regular) GUI pauses on my system. Every 30 seconds (pretty much exactly) the GUI will freeze for maybe .25 to .5 seconds. The mouse stops moving, keys stop echoing and a stopwatch timer briefly pauses. I'm using the Intel Graphics driver available from: https://download.01.org/gfx/ubuntu/13.04/main I've looked in a few places and tried a few things for a solution: I've checked cron and anacron for scheduled processes. I've disabled background processes (eg mysql, postgres, apache) not that these were doing anything anyway I've checked the following posts and tried the suggestions there: Unity GUI pauses/freezes for less than a few seconds How to go about troubleshooting frequent system pauses I've watched the system using top and System Monitor and there are no spikes (or even blips) of cpu usage when the pauses occur. There are no obvious error messages in dmesg or syslog There is loads of free RAM (8GB+) and no swap usage If it helps it's a ZooStorm i5 laptop with a HD4000 GPU, 16GB Ram and an SSD. Any help / suggestions would be very gratefully received.

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  • Toshiba satellite L500 no Wifi anymore!

    - by Benjamin Piller
    I have a Toshiba Satellite L500 with Ubuntu 12.04 and its wifi suddenly stopped working!! I've never seen like that before.. I tried also using external USB wifis but no success. I am not able to turn it on with the function keys nor using rfkill commands and similar WLAN manipulator Commands in the terminal! It was working before for at least 4-5 months!! The computer says it's turned off by hardware. I checked it and the Driver is fine. So why can i not use any Wifi on my computer?? Why it is suddenly disabled? I checked the BIOS too there is enabled the WLAN. I spent 10 hours for searching for solutions but i am out of ideas!!! Please Help!

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  • Numerically stable(ish) method of getting Y-intercept of mouse position?

    - by Fraser
    I'm trying to unproject the mouse position to get the position on the X-Z plane of a ray cast from the mouse. The camera is fully controllable by the user. Right now, the algorithm I'm using is... Unproject the mouse into the camera to get the ray: Vector3 p1 = Vector3.Unproject(new Vector3(x, y, 0), 0, 0, width, height, nearPlane, farPlane, viewProj; Vector3 p2 = Vector3.Unproject(new Vector3(x, y, 1), 0, 0, width, height, nearPlane, farPlane, viewProj); Vector3 dir = p2 - p1; dir.Normalize(); Ray ray = Ray(p1, dir); Then get the Y-intercept by using algebra: float t = -ray.Position.Y / ray.Direction.Y; Vector3 p = ray.Position + t * ray.Direction; The problem is that the projected position is "jumpy". As I make small adjustments to the mouse position, the projected point moves in strange ways. For example, if I move the mouse one pixel up, it will sometimes move the projected position down, but when I move it a second pixel, the project position will jump back to the mouse's location. The projected location is always close to where it should be, but it does not smoothly follow a moving mouse. The problem intensifies as I zoom the camera out. I believe the problem is caused by numeric instability. I can make minor improvements to this by doing some computations at double precision, and possibly abusing the fact that floating point calculations are done at 80-bit precision on x86, however before I start micro-optimizing this and getting deep into how the CLR handles floating point, I was wondering if there's an algorithmic change I can do to improve this? EDIT: A little snooping around in .NET Reflector on SlimDX.dll: public static Vector3 Unproject(Vector3 vector, float x, float y, float width, float height, float minZ, float maxZ, Matrix worldViewProjection) { Vector3 coordinate = new Vector3(); Matrix result = new Matrix(); Matrix.Invert(ref worldViewProjection, out result); coordinate.X = (float) ((((vector.X - x) / ((double) width)) * 2.0) - 1.0); coordinate.Y = (float) -((((vector.Y - y) / ((double) height)) * 2.0) - 1.0); coordinate.Z = (vector.Z - minZ) / (maxZ - minZ); TransformCoordinate(ref coordinate, ref result, out coordinate); return coordinate; } // ... public static void TransformCoordinate(ref Vector3 coordinate, ref Matrix transformation, out Vector3 result) { Vector3 vector; Vector4 vector2 = new Vector4 { X = (((coordinate.Y * transformation.M21) + (coordinate.X * transformation.M11)) + (coordinate.Z * transformation.M31)) + transformation.M41, Y = (((coordinate.Y * transformation.M22) + (coordinate.X * transformation.M12)) + (coordinate.Z * transformation.M32)) + transformation.M42, Z = (((coordinate.Y * transformation.M23) + (coordinate.X * transformation.M13)) + (coordinate.Z * transformation.M33)) + transformation.M43 }; float num = (float) (1.0 / ((((transformation.M24 * coordinate.Y) + (transformation.M14 * coordinate.X)) + (coordinate.Z * transformation.M34)) + transformation.M44)); vector2.W = num; vector.X = vector2.X * num; vector.Y = vector2.Y * num; vector.Z = vector2.Z * num; result = vector; } ...which seems to be a pretty standard method of unprojecting a point from a projection matrix, however this serves to introduce another point of possible instability. Still, I'd like to stick with the SlimDX Unproject routine rather than writing my own unless it's really necessary.

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  • To same computer Remote desktop thrue WRT54G router

    - by Kangarooo
    Cant access from my Same comp same comp to test if all is ok. Tryd all mentioned posibilities. Tryd my ip xxx.xxx.xxx.xxx / localhost with / without :5900 added with / without in "Remote desktop" checked "Configure network automatically to accept connection" with / without in router WRT54G enabled port 5900 forwardet to my comp 192.168.1.3 UPNP is enabled. I can connect to one other comp witch isnt using router and checked "Configure network automatically to accept connection" and to one thrue TENDA W311R+ router where ive put port forwarding to 5900 and there works xxx.xxx.xxx.xxx:5900 Whats wrong? What ive missed?

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  • How can I get my ATI / AMD drivers to work with any kernel above 3.2.0.x?

    - by TorakTu
    How can I get my ATI / AMD drivers to work with any kernel above 3.2.0.x ? WHAT DID WORK Installed original AMD64 version of Ubuntu 12.04 ISO image. Burned DVD and installed which shown kernel 3.2.0-23 to begin with. Got 5.1 surround sound working. Got ATI ( Now its AMD ) video drivers installed for my Radeon HD R6870 Video card from AMD's website. fglrxinfo came up and reported as normal. THE PROBLEM Kernel 3.2.0.x kept locking up so I tried higher kernel versions. But ATI / AMD Drivers do not install on any kernel Above 3.2.0.x WHAT I HAVE TRIED I have gone over this tutorial many times ( https://help.ubuntu.com/community/BinaryDriverHowto/ATI ) and it doesn't work on ANY kernel except 3.2.0.x. The problems I am having here are that the ATI / AMD drivers working for the 12.04 Precise with kernel 3.2.0-23 and 24, But the computer kept locking up. Although all my games would work, the lock ups were random and were constant. So I looked all over the web for 3 days trying to find an answer and the lock up issue was said to just update the kernel. So I did. Have tried many kernels. All of them .. no lock ups. BUT the Restricted AMD drivers from the AMD website will not install. And none of the OpenSource AMD drivers have EVER installed no matter what Kernel or version I tried. EXAMPLE OUTPUT OF 3D TYPE OF ERRORS Javax.media.opengl.GLException: glXGetConfig failed: error code GLX_NO_EXTENSION at com.sun.opengl.impl.x11.X11GLDrawableFactory.glXGetConfig(X11GLDrawableFactory.java:651) at com.sun.opengl.impl.x11.X11GLDrawableFactory.xvi2GLCapabilities(X11GLDrawableFactory.java:350) at com.sun.opengl.impl.x11.X11GLDrawableFactory.chooseGraphicsConfiguration(X11GLDrawableFactory.java:174) at javax.media.opengl.GLCanvas.chooseGraphicsConfiguration(GLCanvas.java:520) at javax.media.opengl.GLCanvas.<init>(GLCanvas.java:131) at haven.HavenPanel.<init>(HavenPanel.java:68) at haven.HavenPanel.<init>(HavenPanel.java:78) at haven.MainFrame.<init>(MainFrame.java:182) at haven.MainFrame.main2(MainFrame.java:306) at haven.MainFrame.access$100(MainFrame.java:34) at haven.MainFrame$7.run(MainFrame.java:360) at java.lang.Thread.run(Thread.java:722) And of course this is what fglrxinfo shows : X Error of failed request: BadRequest (invalid request code or no such operation) Major opcode of failed request: 139 (ATIFGLEXTENSION) Minor opcode of failed request: 66 () Serial number of failed request: 13 Current serial number in output stream: 13 EDIT : I forgot to mention that I DID look at this post over the last few days and it did not help.

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  • SQL 2014 does data the way developers want

    - by Rob Farley
    A post I’ve been meaning to write for a while, good that it fits with this month’s T-SQL Tuesday, hosted by Joey D’Antoni (@jdanton) Ever since I got into databases, I’ve been a fan. I studied Pure Maths at university (as well as Computer Science), and am very comfortable with Set Theory, which undergirds relational database concepts. But I’ve also spent a long time as a developer, and appreciate that that databases don’t exactly fit within the stuff I learned in my first year of uni, particularly the “Algorithms and Data Structures” subject, in which we studied concepts like linked lists. Writing in languages like C, we used pointers to quickly move around data, without a database in sight. Of course, if we had a power failure all this data was lost, as it was only persisted in RAM. Perhaps it’s why I’m a fan of database internals, of indexes, latches, execution plans, and so on – the developer in me wants to be reassured that we’re getting to the data as efficiently as possible. Back when SQL Server 2005 was approaching, one of the big stories was around CLR. Many were saying that T-SQL stored procedures would be a thing of the past because we now had CLR, and that obviously going to be much faster than using the abstracted T-SQL. Around the same time, we were seeing technologies like Linq-to-SQL produce poor T-SQL equivalents, and developers had had a gutful. They wanted to move away from T-SQL, having lost trust in it. I was never one of those developers, because I’d looked under the covers and knew that despite being abstracted, T-SQL was still a good way of getting to data. It worked for me, appealing to both my Set Theory side and my Developer side. CLR hasn’t exactly become the default option for stored procedures, although there are plenty of situations where it can be useful for getting faster performance. SQL Server 2014 is different though, through Hekaton – its In-Memory OLTP environment. When you create a table using Hekaton (that is, a memory-optimized one), the table you create is the kind of thing you’d’ve made as a developer. It creates code in C leveraging structs and pointers and arrays, which it compiles into fast code. When you insert data into it, it creates a new instance of a struct in memory, and adds it to an array. When the insert is committed, a small write is made to the transaction to make sure it’s durable, but none of the locking and latching behaviour that typifies transactional systems is needed. Indexes are done using hashes and using bw-trees (which avoid locking through the use of pointers) and by handling each updates as a delete-and-insert. This is data the way that developers do it when they’re coding for performance – the way I was taught at university before I learned about databases. Being done in C, it compiles to very quick code, and although these tables don’t support every feature that regular SQL tables do, this is still an excellent direction that has been taken. @rob_farley

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  • Are my actual worker threads exceeding the sp_configure 'max worker threads' value?

    Tom Stringer (@SQLife) was working on some HADR testing for a customer to simulate many availability groups and introduce significant load into the system to measure overhead and such. In his quest to do that he was seeing behavior that he couldn’t really explain and so worked with him to uncover what was happening under the covers. Understand Locking, Blocking & Row VersioningRead Kalen Delaney's eBook to understand SQL Server concurrency, and use SQL Monitor to pinpoint excessive blocking and deadlocking. Download free resources.

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  • Parameterized StreamInsight Queries

    - by Roman Schindlauer
    The changes in our APIs enable a set of scenarios that were either not possible before or could only be achieved through workarounds. One such use case that people ask about frequently is the ability to parameterize a query and instantiate it with different values instead of re-deploying the entire statement. I’ll demonstrate how to do this in StreamInsight 2.1 and combine it with a method of using subjects for dynamic query composition in a mini-series of (at least) two blog articles. Let’s start with something really simple: I want to deploy a windowed aggregate to a StreamInsight server, and later use it with different window sizes. The LINQ statement for such an aggregate is very straightforward and familiar: var result = from win in stream.TumblingWindow(TimeSpan.FromSeconds(5))               select win.Avg(e => e.Value); Obviously, we had to use an existing input stream object as well as a concrete TimeSpan value. If we want to be able to re-use this construct, we can define it as a IQStreamable: var avg = myApp     .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) =>         from win in s.TumblingWindow(w)         select win.Avg(e => e.Value)); The DefineStreamable API lets us define a function, in our case from a IQStreamable (the input stream) and a TimeSpan (the window length) to an IQStreamable (the result). We can then use it like a function, with the input stream and the window length as parameters: var result = avg(stream, TimeSpan.FromSeconds(5)); Nice, but you might ask: what does this save me, except from writing my own extension method? Well, in addition to defining the IQStreamable function, you can actually deploy it to the server, to make it re-usable by another process! When we deploy an artifact in V2.1, we give it a name: var avg = myApp     .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) =>         from win in s.TumblingWindow(w)         select win.Avg(e => e.Value))     .Deploy("AverageQuery"); When connected to the same server, we can now use that name to retrieve the IQStreamable and use it with our own parameters: var averageQuery = myApp     .GetStreamable<IQStreamable<SourcePayload>, TimeSpan, double>("AverageQuery"); var result = averageQuery(stream, TimeSpan.FromSeconds(5)); Convenient, isn’t it? Keep in mind that, even though the function “AverageQuery” is deployed to the server, its logic will still be instantiated into each process when the process is created. The advantage here is being able to deploy that function, so another client who wants to use it doesn’t need to ask the author for the code or assembly, but just needs to know the name of deployed entity. A few words on the function signature of GetStreamable: the last type parameter (here: double) is the payload type of the result, not the actual result stream’s type itself. The returned object is a function from IQStreamable<SourcePayload> and TimeSpan to IQStreamable<double>. In the next article we will integrate this usage of IQStreamables with Subjects in StreamInsight, so stay tuned! Regards, The StreamInsight Team

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