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• How to terminate a request in JSP (not the "return;")

  - by Genom

  I am programming a website with JSP. There are pages where user must be logged in to see it. If they are not logged in, they should see a login form. I have seen in a php code that you can make a .jsp page (single file), which checkes, whether the user is logged in or not. If not it will show the login form. If the user is logged in, nothing will be done. So in order to do that I use this structure in my JSPs: Headers, menus, etc. etc... normal stuff which would be shown such as body, footer to a logged in user. This structure is very easy to apply to all webpages. So I don't have to apply checking algorithm to each webpage! I can simply add this "" and the page is secure! So my problem is that if the user is not logged in, then only the log in form should be shown and the footer. So code should bypass the body. Therefore structured my checklogin.jsp so: If user is not logged in show the login form and footer and terminate request. The problem is that I don't know how to terminate the request... If I use "return;" then only the checklogin.jsp stops but server continues to process parent page! Therefore page has 2 footers! (1 from parent page and 1 from checklogin.jsp). How can I avoid this? (There is exit(); in php for this by the way!) Thanks for any suggestions!

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• How can I provide property-level string formatting?

  - by jhubsharp

  Not sure if the question wording is accurate, but here's what I want to do: I want to databind a class with some strings in it: class MyClass { public string MyProperty { get; set; } public string MyProperty2 { get; set; } } When databinding, everything behaves normally. On the back end, I'm writing to a file and I want MyProperty2 to always be encrypted using some encryption algorithm. I want my back-end code to write each string without needing to know that encryption is required (I want the class to know it should be encrypted, not the consumer). Can I do this with a type converter, or something similar? EDIT: There are other scenarios as well. Some booleans I want to format as "Y" or "N", other booleans I want formatted as "Enabled" / "Disabled", etc. I can write (and have written) helper methods and let the file writer call the helper methods as appropriate, I'm just wondering if there's a way to do this without the file writer needing to know which objects need which kind of formatting and let the objects tell that to the file writer.

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• Integrating jQuery autocomplete with Google site search

  - by user1715700

  I have a bit of an odd situation. I have to implement search on a public facing website -but, that search must be able to search both web pages and have an autocomplete/suggestion functionality that comes from a list of terms that are in a DB table. So, I'm wondering a couple things: 1) should I be looking at Google search and jQuery autocomplete? 2) is there something else I should be looking at instead? 3) if this is the right path to be heading down are the enough pointers on implementation? The crux of my problem is that the terms that I need to use for the autocomplete/suggest functionality reside within a database and not on the webpages. So, I thought Google would be appropriate for search the webpages and that I could sort of fill in the blanks so to speak with these terms from the DB. I'm going to say that there are roughly 20-40,000 terms or so that need autocomplete. But that is really just a very rough guess -it could be less. I'm open to ideas and not really married to any particular solution. However, I will admit to liking the ideas of offloading the search to Google. I hear they have a good algorithm ;) Any ideas, thoughts, or leads are greatly appreciated!

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• How duplicate an object in a list and update property of duplicated objects ?

  - by user359706

  Hello What would be the best way to duplicate an object placed in a list of items and change a property of duplicated objects ? I thought proceed in the following manner: - get object in the list by "ref" + "article" - Cloned the found object as many times as desired (n times) - Remove the object found - Add the clones in the list What do you think? A concrete example: Private List<Product> listProduct; listProduct= new List<Product>(); Product objProduit_1 = new Produit; objProduct_1.ref = "001"; objProduct_1.article = "G900"; objProduct_1.quantity = 30; listProducts.Add(objProduct_1); ProductobjProduit_2 = new Product; objProduct_2.ref = "002"; objProduct_2.article = "G900"; objProduct_2.quantity = 35; listProduits.Add(objProduct_2); desired method: public void updateProductsList(List<Product> paramListProducts,Produit objProductToUpdate, int32 nbrDuplication, int32 newQuantity){ ... } Calling method example: updateProductsList(listProducts,objProduct_1,2,15); Waiting result: Replace follow object : ref = "001"; article = "G900"; quantite = 30; By: ref = "001"; article = "G900"; quantite = 15; ref = "001"; article = "G900"; quantite = 15; The Algorithm is correct? Would you have an idea of the method implementation "updateProductsList" Thank you in advance for your help.

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• Infrastructure for high transactional system (language & hosting suggestion help)

  - by RPS

  Some of our friends (University students) are trying to develop a twitter type application, I want to plan for at least 1000 transactions per second (I know it's wishful thinking) for initial launch. This involves several people connecting and getting updates and posting (text + images) to site. In the back end db will server the data and also calculates rankings of what to push to user based on complex algorithm on the fly real-time. Our group is familiar with Java and Tomcat/MySQL. We can also easily learn/code in PHP/MySQL. What is the best suited platform for our purpose ? Though Java seem to be easy to implement for us I am afraid that hosting will be a bit difficult. I could find cloud based php hosting services (like rackspace cloudsites) at reasonable cost. Amazon EC2 is a bit over our heads to manage on day-to-day. Also any recommendation on hosting ? (PHP or Java) We don't have millions in seed money but about $20K to start with. Any advice on above or any thing in general approach is much appreciated.

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• Why this doesnt't work in C++?

  - by user3377450

  I'm doing something and I have this: //main.cpp file template<typename t1, typename t2> std::ostream& operator<<(std::ostream& os, const std::pair<t1, t2>& pair) { return os << "< " << pair.first << " , " << pair.second << " >"; } int main() { std::map<int, int> map = { { 1, 2 }, { 2, 3 } }; std::cout << *map.begin() << std::endl;//This works std::copy(map.begin(), map.end(), std::ostream_iterator<std::pair<int,int> >(std::cout, " "));//this doesn't work } I guess this is not working because in the std::copy algorithm the operator isn't defined, but what can I do?

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• Java getMethod with subclass parameter

  - by SelectricSimian

  I'm writing a library that uses reflection to find and call methods dynamically. Given just an object, a method name, and a parameter list, I need to call the given method as though the method call were explicitly written in the code. I've been using the following approach, which works in most cases: static void callMethod(Object receiver, String methodName, Object[] params) { Class<?>[] paramTypes = new Class<?>[params.length]; for (int i = 0; i < param.length; i++) { paramTypes[i] = params[i].getClass(); } receiver.getClass().getMethod(methodName, paramTypes).invoke(receiver, params); } However, when one of the parameters is a subclass of one of the supported types for the method, the reflection API throws a NoSuchMethodException. For example, if the receiver's class has testMethod(Foo) defined, the following fails: receiver.getClass().getMethod("testMethod", FooSubclass.class).invoke(receiver, new FooSubclass()); even though this works: receiver.testMethod(new FooSubclass()); How do I resolve this? If the method call is hard-coded there's no issue - the compiler just uses the overloading algorithm to pick the best applicable method to use. It doesn't work with reflection, though, which is what I need. Thanks in advance!

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• [PHP] Does unsetting array values during iterating save on memory?

  - by saturn_rising

  Hello fellow code warriors, This is a simple programming question, coming from my lack of knowledge of how PHP handles array copying and unsetting during a foreach loop. It's like this, I have an array that comes to me from an outside source formatted in a way I want to change. A simple example would be: $myData = array('Key1' => array('value1', 'value2')); But what I want would be something like: $myData = array([0] => array('MyKey' => array('Key1' => array('value1', 'value2')))); So I take the first $myData and format it like the second $myData. I'm totally fine with my formatting algorithm. My question lies in finding a way to conserve memory since these arrays might get a little unwieldy. So, during my foreach loop I copy the current array value(s) into the new format, then I unset the value I'm working with from the original array. E.g.: $formattedData = array(); foreach ($myData as $key => $val) { // do some formatting here, copy to $reformattedVal $formattedData[] = $reformattedVal; unset($myData[$key]); } Is the call to unset() a good idea here? I.e., does it conserve memory since I have copied the data and no longer need the original value? Or, does PHP automatically garbage collect the data since I don't reference it in any subsequent code? The code runs fine, and so far my datasets have been too negligible in size to test for performance differences. I just don't know if I'm setting myself up for some weird bugs or CPU hits later on. Thanks for any insights. -sR

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• Generic list/sublist handling

  - by user628661

  Let's say we have a class class ComplexCls { public int Fld1; public string Fld2; //could be more fields } class Cls { public int SomeField; } and then some code class ComplexClsList: List<ComplexCls>; ComplexClsList myComplexList; // fill myComplexList // same for Cls class ClsList : List<Cls>; ClsList myClsList; We want to populate myClsList from myComplexList, something like (pseudocode): foreach Complexitem in myComplexList { Cls ClsItem = new Cls(); ClsItem.SomeField = ComplexItem.Fld1; } The code to do this is easy and will be put in some method in myClsList. However I'd like to design this as generic as possible, for generic ComplexCls. Note that the exact ComplexCls is known at the moment of using this code, only the algorithm shd be generic. I know it can be done using (direct) reflection but is there other solution? Let me know if the question is not clear enough. (probably isn't). [EDIT] Basically, what I need is this: having myClsList, I need to specify a DataSource (ComplexClsList) and a field from that DataSource (Fld1) that will be used to populate my SomeField

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• Fedora 12 Wireless problems (Intel Wireless 4965AGN Card)

  - by Ninefingers

  Hi All, I'm having an interesting experience with my wireless card at the moment. Basically, it does like this: I connect to the local wireless network (netgear router) It works, briefly, allowing me to browse a webpage or maybe two, if I'm lucky. It then stops working / sending any packets, whilst reported still connected. Now, me being me I've had a look to see what I can find. wpa_supplicant.log looks like this: Trying to associate with valid_mac:a2:30 (SSID='vennardwireless' freq=2462 MHz) Associated with valid_mac:a2:30 WPA: Key negotiation completed with valid_mac:a2:30 [PTK=CCMP GTK=TKIP] CTRL-EVENT-CONNECTED - Connection to valid_mac:a2:30 completed (reauth) [id=0 id_str=] CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys So that's working fine. dmesg | grep "*iwl*" spits out this: iwlagn: Intel(R) Wireless WiFi Link AGN driver for Linux, 1.3.27kds iwlagn: Copyright(c) 2003-2009 Intel Corporation iwlagn 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17 iwlagn 0000:03:00.0: setting latency timer to 64 iwlagn 0000:03:00.0: Detected Intel Wireless WiFi Link 4965AGN REV=0x4 iwlagn 0000:03:00.0: Tunable channels: 13 802.11bg, 19 802.11a channels iwlagn 0000:03:00.0: irq 32 for MSI/MSI-X phy0: Selected rate control algorithm 'iwl-agn-rs' iwlagn 0000:03:00.0: firmware: requesting iwlwifi-4965-2.ucode iwlagn 0000:03:00.0: loaded firmware version 228.61.2.24 Registered led device: iwl-phy0::radio Registered led device: iwl-phy0::assoc Registered led device: iwl-phy0::RX Registered led device: iwl-phy0::TX iwlagn 0000:03:00.0: iwl_tx_agg_start on ra = 00:24:b2:32:a3:30 tid = 0 iwlagn 0000:03:00.0: iwl_tx_agg_start on ra = 00:24:b2:32:a3:30 tid = 0 So that's working too. I can also ping 192.168.0.1 -I wlan0 and arping 192.168.0.1 -I wlan0 the router until the network falls over. uname -r:2.6.32.10-90.fc12.x86_64. Laptop is a Core2 Duo (2Ghz) with 3GB RAM. Other symptoms I've noticed are that wireshark freezes when I capture on the "broken" interface until I disconnect. Am using networkmanager as per normal. Stupidly, I can connect to the same router via eth0/a cat6 cable just fine. Everyone else can connect to the AP fine (from Windows). Yes, I'm sat right next to it and not trying to access a hotspot the other side of the world. Any ideas? Is this a broken update? (I intend to reboot and test an older kernel later)? Anyone else come across this? Edit: iwconfig wlan0 rate auto is the settings I'm using for rates. Also, according to networkmanager the network is still connected. Thanks for any pointers / advice.

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• Unix sort keys cause performance problems

  - by KenFar

  My data: It's a 71 MB file with 1.5 million rows. It has 6 fields All six fields combine to form a unique key - so that's what I need to sort on. Sort statement: sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 -k6,6 -o output.csv input.csv The problem: If I sort without keys, it takes 30 seconds. If I sort with keys, it takes 660 seconds. I need to sort with keys to keep this generic and useful for other files that have non-key fields as well. The 30 second timing is fine, but the 660 is a killer. More details using unix time: sort input.csv -o output.csv = 28 seconds sort -t ',' -k1 input.csv -o output.csv = 28 seconds sort -t ',' -k1,1 input.csv -o output.csv = 64 seconds sort -t ',' -k1,1 -k2,2 input.csv -o output.csv = 194 seconds sort -t ',' -k1,1 -k2,2 -k3,3 input.csv -o output.csv = 328 seconds sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 input.csv -o output.csv = 483 seconds sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 input.csv -o output.csv = 561 seconds sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 -k6,6 input.csv -o output.csv = 660 seconds I could theoretically move the temp directory to SSD, and/or split the file into 4 parts, sort them separately (in parallel) then merge the results, etc. But I'm hoping for something simpler since looks like sort is just picking a bad algorithm. Any suggestions? Testing Improvements using buffer-size: With 2 keys I got a 5% improvement with 8, 20, 24 MB and best performance of 8% improvement with 16MB, but 6% worse with 128MB With 6 keys I got a 5% improvement with 8, 20, 24 MB and best performance of 9% improvement with 16MB. Testing improvements using dictionary order (just 1 run each): sort -d --buffer-size=8M -t ',' -k1,1 -k2,2 input.csv -o output.csv = 235 seconds (21% worse) sort -d --buffer-size=8M -t ',' -k1,1 -k2,2 input.csv -o ouput.csv = 232 seconds (21% worse) conclusion: it makes sense that this would slow the process down, not useful Testing with different file system on SSD - I can't do this on this server now. Testing with code to consolidate adjacent keys: def consolidate_keys(key_fields, key_types): """ Inputs: - key_fields - a list of numbers in quotes: ['1','2','3'] - key_types - a list of types of the key_fields: ['integer','string','integer'] Outputs: - key_fields - a consolidated list: ['1,2','3'] - key_types - a list of types of the consolidated list: ['string','integer'] """ assert(len(key_fields) == len(key_types)) def get_min(val): vals = val.split(',') assert(len(vals) <= 2) return vals[0] def get_max(val): vals = val.split(',') assert(len(vals) <= 2) return vals[len(vals)-1] i = 0 while True: try: if ( (int(get_max(key_fields[i])) + 1) == int(key_fields[i+1]) and key_types[i] == key_types[i+1]): key_fields[i] = '%s,%s' % (get_min(key_fields[i]), key_fields[i+1]) key_types[i] = key_types[i] key_fields.pop(i+1) key_types.pop(i+1) continue i = i+1 except IndexError: break # last entry return key_fields, key_types While this code is just a work-around that'll only apply to cases in which I've got a contiguous set of keys - it speeds up the code by 95% in my worst case scenario.

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• How to set up a mini call center?

  - by Ralph

  I'm trying to figure out how to set up a miniature call center for a small business. Like, for 1-4 people to take calls, but hopefully expandable to more. We want to accept nation-wide calls, and then I guess distribute the calls among the available agents. If no one is available, I guess it should either put them in a queue and play some annoying music for them, or forward to call to an agent who has least-recently taken a call who can then quickly answer and say "please hold" until they're done their call. We want to have one phone number that customers can call. I guess we then need some kind of ACD system which would take each call and forward it to an agent based on some algorithm? Then we would need to purchase a separate phone line for each agent, plus one just for the distributor? Or do we need several "extra" lines to maintain a queue (one for each customer waiting too)? This "ACD" thing, is it just a device that you would plug a phone line into (or several?), and maybe connect to a computer, aided by some software? Or is a subscription thing that I would need from my local telephone provider? Next, the business we're running, the callers will be repeat customers. It would be helpful to automatically pull up their profile based on the incoming number. The "software" our agents will be running will just be a website where they can log in (preferably from home) and then enter some information they would obtain through the call. So, the system would have to somehow interface with the website if possible. If not, we'll just have to ask each customer for an identifier (phone number, username, customer number, or something). Is this possible? I guess each computer would need a device that the call would pass through, and then if I can somehow hook into that, then I can write some software that will interface with the site. So, where do I start? What hardware do we need to buy? What subscriptions do we need? We were thinking this magicJack might help us in accepting long-distance calls for cheaper, but my understanding is that they provide you with some weird-looking number, is there a way we could "mask" it with our toll-free number? And then pass the incoming calls through the distributor system, which would then get passed to the call-accepting device which would both allow an agent to answer the call and have a software hook? (I realize this might be partially out of the scope of SU, but I wasn't sure where else to ask. It is about computer(-aided) hardware and software anyway.) P.S.: I don't need any of that "press 1 to talk to..." or "say xyz to..." junk. Just a straight-forward, connect-to-next-available-agent system.

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• Linux boot on a raid1 software raid ?

  - by azera

  Hello I am trying to convert my single disk boot to a raid1 boot So far here is what i have: I sucessfully create the raid 1 as degraded with the new drive alone, I copied all the data on it I can mount that raid 1, see its files etc I already have a raid5 that is working on the same box (although not booting on it) I have installed grub on both drive When grub boot, it loads the kernel alright, but during the kernel boot it fails to load the "root block device" The kernel tells me : 1 - detected that root device is an md device 2 - determining root devices 3 - mounting root 4 - mounting /dev/md125 on /newroot failed: input/output error. Please enter another root device: ... At this point, if I enter /dev/sda3 (my "old" root device that isn't converted to raid yet) everything boots fine without the root. The /dev/md125 device is indeed created but it seems to be created after the error happens, as in it creates it after loading the device, when mdadm is loaded. Somehow it looks like it can't/doesn't load the raid array before it needs to mount it, and I don't know how I can solve that. My config files (taken from the system once it boots with sda3 as root device): $ cat /etc/mdadm.conf ARRAY /dev/md/md0-r5 metadata=0.90 UUID=1a118934:c831bdb3:64188b84:66721085 ARRAY /dev/md125 metadata=0.90 UUID=48ec4190:a80d4dde:64188b84:66721085 $ cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] [raid0] [raid10] md125 : active raid1 sdc3[1] 477853312 blocks [2/1] [_U] md127 : active raid5 sdd[0] sdf[3] sdb[2] sde[1] 4395415488 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU] unused devices: <none> $ cat /boot/grub/menu.lst default 0 timeout 8 splashimage=(hd0,0)/boot/grub/splash.xpm.gz title Gentoo Linux 2.6.31-r10 root (hd0,0) #kernel /boot/kernel-genkernel-x86_64-2.6.31-gentoo-r10 root=/dev/ram0 real_root=/dev/sda3 kernel /boot/kernel-genkernel-x86_64-2.6.31-gentoo-r10 root=/dev/md125 md=125,/dev/sdc3,/dev/sda3 initrd /boot/initramfs-genkernel-x86_64-2.6.31-gentoo-r10 # blkid /dev/sda1: UUID="89fee223-b845-4e0a-8a0b-e6cf695d5bcf" TYPE="ext2" /dev/sda2: UUID="a72296a8-d7d4-447f-a34b-ee920fd1a767" TYPE="swap" /dev/sda3: UUID="97eb0a6a-c385-4a9d-bf74-c0bab1fa4dc1" TYPE="ext3" /dev/sdb: UUID="1a118934-c831-bdb3-6418-8b8466721085" TYPE="linux_raid_member" /dev/sdc1: UUID="d36537fd-19a0-b8a3-6418-8b8466721085" TYPE="linux_raid_member" /dev/sdd: UUID="1a118934-c831-bdb3-6418-8b8466721085" TYPE="linux_raid_member" /dev/sde: UUID="1a118934-c831-bdb3-6418-8b8466721085" TYPE="linux_raid_member" /dev/md127: UUID="13a41589-4cf1-4c04-91ca-37484182c783" TYPE="ext4" /dev/sdf: UUID="1a118934-c831-bdb3-6418-8b8466721085" TYPE="linux_raid_member" /dev/sdc2: UUID="a1916397-1b48-45d7-9f98-73aa521e882f" TYPE="swap" /dev/sdc3: UUID="48ec4190-a80d-4dde-6418-8b8466721085" TYPE="linux_raid_member" /dev/md125: UUID="c947ed64-1d4d-4d1d-b4d2-24669fff916e" SEC_TYPE="ext2" TYPE="ext3" # mdadm -E mdadm: No devices to examine # fdisk -l Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xe975e9fc Device Boot Start End Blocks Id System /dev/sda1 1 5 40131 83 Linux /dev/sda2 6 1311 10490445 82 Linux swap / Solaris /dev/sda3 1312 60801 477853425 83 Linux Disk /dev/sdc: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xe975e9fc Device Boot Start End Blocks Id System /dev/sdc1 1 5 40131 83 Linux /dev/sdc2 6 1311 10490445 82 Linux swap / Solaris /dev/sdc3 1312 60801 477853425 83 Linux Disk /dev/md125: 489.3 GB, 489321791488 bytes 2 heads, 4 sectors/track, 119463328 cylinders Units = cylinders of 8 * 512 = 4096 bytes Disk identifier: 0x00000000 Disk /dev/md125 doesn't contain a valid partition table

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• How to block subreddits with BIND9?

  - by user1391189

  Please help me block NSFW subreddits like this one (http://www.reddit.com/r/NSFW/) I would like to keep access to SFW subreddits, but block certain subreddits that are distracting or NSFW. I know how to filter domains. (see files below) But how do I apply the filter only to certain subreddits? So far I have set up the following files: blocklist.conf zone "adimages.go.com" { type master; file "dummy-block"; }; zone "admonitor.net" { type master; file "dummy-block"; }; zone "ads.specificpop.com" { type master; file "dummy-block"; }; ... named.conf options { allow-query { 127.0.0.1; }; allow-recursion { 127.0.0.1; }; directory "c:\bind\etc"; notify no; }; zone "." IN { type hint; file "c:\bind\etc\named.root"; }; zone "localhost" IN { allow-update { none; }; file "c:\bind\etc\localhost.zone"; type master; }; zone "0.0.127.in-addr.arpa" IN { allow-update { none; }; file "c:\bind\etc\named.local"; type master; }; key "rndc-key" { algorithm hmac-md5; secret "O5VdbBKKEMzuLYjM60CxwuLLURFA6peDYHCBvZCqjoa6KtL1ggD7OTLeLtnu2jR5I5cwA/MQ8UdHc+9tMJRSiw=="; }; controls { inet 127.0.0.1 port 953 allow { 127.0.0.1; } keys { "rndc-key"; }; }; //Blocklist include "c:\bind\etc\blocklist.conf"; dummy-block $TTL 604800 @ IN SOA localhost. root.localhost. ( 2 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; @ IN NS localhost. @ IN A 127.0.0.1 * IN A 127.0.0.1

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• Why is site serving different SSL certs to different browsers?

  - by TRiG

  The SSL certificate on menswearireland.com and on www.menswearireland.com works fine on Safari, Chrome, SeaMonkey, K-Meleon, QtWeb, Firefox, and Opera. However, Internet Explorer claims that there is an error: The security certificate presented by this website was not issued by a trusted certificate authority. The security certificate presented by this website was issued for a different website's address. Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server. Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0; Trident/5.0) Another site hosted on the same managed server shows no errors: achill-fieldschool.com and www.achill-fieldschool.com work fine on IE, even though as far as I can tell the certificate is set up identically. What am I doing wrong? This is a LAMPP server running Plesk. It looks like the server is showing different certificates to different clients. To some clients it shows a RapidSSL certificate made out to www.menswearireland.com with menswearireland.com as a valid alternative name. To other clients, it shows a Parallels Panel certificate, made out to Parallels Panel. Here are results from a few different online SSL checkers: most say it's fine, while two show errors. Three online checkers say it's valid Comodo SSL Check shows it as valid DigiCert SSL Check shows it as valid SSL Shopper SSL Check shows it as valid Common name: www.menswearireland.com SANs: www.menswearireland.com, menswearireland.com Valid from October 2, 2012 to November 4, 2013 Serial Number: 559425 (0x88941) Signature Algorithm: sha1WithRSAEncryption Issuer: RapidSSL CA Another online checker seems to see a completely different certificate GeoCerts SSL Check shows it as invalid Common name: Parallels Panel Organization: Parallels Valid from August 15, 2012 to August 15, 2013 Issuer: Parallels Panel Another online checker sees more than one certificate Symantic SSL Check shows it as invalid The certificate installation checker connected to the Web server and read its certificates, but could not determine which is the primary certificate for the Web server. Incidentally, on both menswearireland.com and achill-fieldschool.com the homepage will redirect from HTTPS to HTTP. To see SSL details, visit the page /account on both (that page will redirect from HTTP to HTTPS). I’ve found more information in a more detailed online SSL checker. https://www.ssllabs.com/ssltest/analyze.html?d=menswearireland.com This site works only in browsers with SNI support My understanding is that SNI (RFC 6066) is a method for putting many SSL sites on one shared IP address and port. This does not work on Internet Explorer on older versions of Windows (this has to do with the version of Windows, not the version of Internet Explorer). However, all our SSL sites are on a unique IP address, so we shouldn’t need SNI.

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• flashcache with mdadm and LVM

  - by Backtogeek

  I am having trouble setting up flashcache on a system with LVM and mdadm, I suspect I am either just missing an obvious step or getting some mapping wrong and hoped someone could point me in the right direction? system info: CentOS 6.4 64 bit mdadm config md0 : active raid1 sdd3[2] sde3[3] sdf3[4] sdg3[5] sdh3[1] sda3[0] 204736 blocks super 1.0 [6/6] [UUUUUU] md2 : active raid6 sdd5[2] sde5[3] sdf5[4] sdg5[5] sdh5[1] sda5[0] 3794905088 blocks super 1.1 level 6, 512k chunk, algorithm 2 [6/6] [UUUUUU] md3 : active raid0 sdc1[1] sdb1[0] 250065920 blocks super 1.1 512k chunks md1 : active raid10 sdh1[1] sda1[0] sdd1[2] sdf1[4] sdg1[5] sde1[3] 76749312 blocks super 1.1 512K chunks 2 near-copies [6/6] [UUUUUU] pcsvan PV /dev/mapper/ssdcache VG Xenvol lvm2 [3.53 TiB / 3.53 TiB free] Total: 1 [3.53 TiB] / in use: 1 [3.53 TiB] / in no VG: 0 [0 ] flashcache create command used: flashcache_create -p back ssdcache /dev/md3 /dev/md2 pvdisplay --- Physical volume --- PV Name /dev/mapper/ssdcache VG Name Xenvol PV Size 3.53 TiB / not usable 106.00 MiB Allocatable yes PE Size 128.00 MiB Total PE 28952 Free PE 28912 Allocated PE 40 PV UUID w0ENVR-EjvO-gAZ8-TQA1-5wYu-ISOk-pJv7LV vgdisplay --- Volume group --- VG Name Xenvol System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 2 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 1 Max PV 0 Cur PV 1 Act PV 1 VG Size 3.53 TiB PE Size 128.00 MiB Total PE 28952 Alloc PE / Size 40 / 5.00 GiB Free PE / Size 28912 / 3.53 TiB VG UUID 7vfKWh-ENPb-P8dV-jVlb-kP0o-1dDd-N8zzYj So that is where I am at, I thought that was the job done however when creating a logical volume called test and mounting it is /mnt/test the sequential write is pathetic, 60 ish MB/s /dev/md3 has 2 x SSD's in Raid0 which alone is performing at around 800 MB/s sequential write and I am trying to cache /dev/md2 which is 6 x 1TB drives in raid6 I have read a number of pages through the day and some of them here, it is obvious from the results that the cache is not functioning but I am unsure why. I have added the filter line in the lvm.conf filter = [ "r|/dev/sdb|", "r|/dev/sdc|", "r|/dev/md3|" ] It is probably something silly but the cache is clearly performing no writes so I suspect I am not mapping it or have not mounted the cache correctly. dmsetup status ssdcache: 0 7589810176 flashcache stats: reads(142), writes(0) read hits(133), read hit percent(93) write hits(0) write hit percent(0) dirty write hits(0) dirty write hit percent(0) replacement(0), write replacement(0) write invalidates(0), read invalidates(0) pending enqueues(0), pending inval(0) metadata dirties(0), metadata cleans(0) metadata batch(0) metadata ssd writes(0) cleanings(0) fallow cleanings(0) no room(0) front merge(0) back merge(0) force_clean_block(0) disk reads(9), disk writes(0) ssd reads(133) ssd writes(9) uncached reads(0), uncached writes(0), uncached IO requeue(0) disk read errors(0), disk write errors(0) ssd read errors(0) ssd write errors(0) uncached sequential reads(0), uncached sequential writes(0) pid_adds(0), pid_dels(0), pid_drops(0) pid_expiry(0) lru hot blocks(31136000), lru warm blocks(31136000) lru promotions(0), lru demotions(0) Xenvol-test: 0 10485760 linear I have included as much info as I can think of, look forward to any replies.

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• BIND DNS server (Windows) - Unable to access my local domain from other computers on LAN

  - by Ricardo Saraiva

  I have a BIND DNS server running on my Windows 7 development machine and I'm serving pages with WAMPSERVER. My ideia is to develop some tools (in PHP) for my intranet at work and I want them to be accessible via LAN in this format: http://tools.mycompany.com I've already placed BIND and I can access http://tools.mycompany.com on the machine that holds BIND server, but I cannot access it from other LAN computers. I've done the following on my router: defined static IP's for all LAN computers set Port Forwarding to my server (remember: it serves DNS and Web pages) set DNS server configuration to point to my LAN server On LAN computers, I went to Local Area Network properties and also changed the DNS server IP in order to point to my local DNS server. If it helps, here is my named.conf file: options { directory "c:\windows\SysWOW64\dns\etc"; forwarders {127.0.0.1; 8.8.8.8; 8.8.4.4;}; pid-file "run\named.pid"; allow-transfer { none; }; recursion no; }; logging{ channel my_log{ file "log\named.log" versions 3 size 2m; severity info; print-time yes; print-severity yes; print-category yes; }; category default{ my_log; }; }; zone "mycompany.com" IN { type master; file "zones\db.mycompany.com.txt"; allow-transfer { none; }; }; key "rndc-key" { algorithm hmac-md5; secret "qfApxn0NxXiaacFHpI86Rg=="; }; controls { inet 127.0.0.1 port 953 allow { 127.0.0.1; } keys { "rndc-key"; }; }; ...and a single zone I've defined - file db.mycompany.com.txt: $TTL 6h @ IN SOA tools.mycompany.com. hostmaster.mycompany.com. ( 2014042601 10800 3600 604800 86400 ) @ NS tools.mycompany.com. tools IN A 192.168.1.4 www IN A 192.168.1.4 On the file above 192.168.1.4 is the IP of the local machine inside my LAN. Can someone help me here? I need my web pages to be accessible from other computers inside my LAN using my custom domain name. I've tried on other computers and they can access my server via http://192.168.1.4/, but no able when using http://tools.mycompany.com . Please, consider the following: I'm completely new to BIND I have basic knowledge in Apache configuration Thanks a lot for your help.

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• Switch flooding when bonding interfaces in Linux

  - by John Philips

  +--------+ | Host A | +----+---+ | eth0 (AA:AA:AA:AA:AA:AA) | | +----+-----+ | Switch 1 | (layer2/3) +----+-----+ | +----+-----+ | Switch 2 | +----+-----+ | +----------+----------+ +-------------------------+ Switch 3 +-------------------------+ | +----+-----------+----+ | | | | | | | | | | eth0 (B0:B0:B0:B0:B0:B0) | | eth4 (B4:B4:B4:B4:B4:B4) | | +----+-----------+----+ | | | Host B | | | +----+-----------+----+ | | eth1 (B1:B1:B1:B1:B1:B1) | | eth5 (B5:B5:B5:B5:B5:B5) | | | | | | | | | +------------------------------+ +------------------------------+ Topology overview Host A has a single NIC. Host B has four NICs which are bonded using the balance-alb mode. Both hosts run RHEL 6.0, and both are on the same IPv4 subnet. Traffic analysis Host A is sending data to Host B using some SQL database application. Traffic from Host A to Host B: The source int/MAC is eth0/AA:AA:AA:AA:AA:AA, the destination int/MAC is eth5/B5:B5:B5:B5:B5:B5. Traffic from Host B to Host A: The source int/MAC is eth0/B0:B0:B0:B0:B0:B0, the destination int/MAC is eth0/AA:AA:AA:AA:AA:AA. Once the TCP connection has been established, Host B sends no further frames out eth5. The MAC address of eth5 expires from the bridge tables of both Switch 1 & Switch 2. Switch 1 continues to receive frames from Host A which are destined for B5:B5:B5:B5:B5:B5. Because Switch 1 and Switch 2 no longer have bridge table entries for B5:B5:B5:B5:B5:B5, they flood the frames out all ports on the same VLAN (except for the one it came in on, of course). Reproduce If you ping Host B from a workstation which is connected to either Switch 1 or 2, B5:B5:B5:B5:B5:B5 re-enters the bridge tables and the flooding stops. After five minutes (the default bridge table timeout), flooding resumes. Question It is clear that on Host B, frames arrive on eth5 and exit out eth0. This seems ok as that's what the Linux bonding algorithm is designed to do - balance incoming and outgoing traffic. But since the switch stops receiving frames with the source MAC of eth5, it gets timed out of the bridge table, resulting in flooding. Is this normal? Why aren't any more frames originating from eth5? Is it because there is simply no other traffic going on (the only connection is a single large data transfer from Host A)? I've researched this for a long time and haven't found an answer. Documentation states that no switch changes are necessary when using mode 6 of the Linux interface bonding (balance-alb). Is this behavior occurring because Host B doesn't send any further packets out of eth5, whereas in normal circumstances it's expected that it would? One solution is to setup a cron job which pings Host B to keep the bridge table entries from timing out, but that seems like a dirty hack.

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• Synchronize the same set of files to 2 different locations with 2 different programs for 2 different purposes

  - by Hedgetrimmer

  Because of stupid questionable IT policies at my not-to-be-named place of occupation, I have been (and will be, for the forseeable future) carrying on an external hard drive a unison-synchronized copy of all of my documents and code, including code which resides in some of my "dotfiles" and other code which resides in ~/bin (things I've made are there because ~/bin is in my $PATH) along with some cruft generated (and to be generated) by conscript and its related "giter8" templating system for Scala project boilerplates. Despite this, I do use a symlinking program to store all of my important dotfiles in a subdirectory. Thanks to that somewhat complicated setup, I have resorted to making a directory full of symlinks to every directory (or file, as is the case with stuff under ~/bin) that I want synchronized, and then follow = True is in my unison profile. It happens to be that this collection of odds and ends—plus an automatically-generated text file containing every package installed on my system—is everything under ~ that needs to be backed up to a remote (rsync-over-ssh) host with client-side encryption and signing from GPG. I already believe that duplicity is the most appropriate program to do that. What isn't as clear-cut is how to make duplicity use the exact same set of files when it runs a backup; it would be simple if duplicity would follow symlinks, but it does not and the manpage lists no option for enabling any such behavior. Comparing unison's file selection algorithm to duplicity's, I don't think I can write a program that could compute a ruleset for one program given one for the other. For the record, I would rather not keep the symlinks manually synchronized with duplicity file-selection rules, as they can change thanks to the above-mentioned complications regarding ~/bin. I don't think running duplicity on the external hard disk is such a good idea either; I usually keep that hard disk unmounted and unplugged in case of a power failure or other physical problem with the computer, plus I'm not sure about duplicity's performance given that: the hard disk is NTFS-formatted in order to be useable at my Windows-imprisoned place of occupation. despite being a USB 3.0 disk, my computer has no USB 3.0 ports so it acts as a USB 2.0 disk. How can I have duplicity (or is there a better program that I have overlooked?) back up the exact same set of files that is bidirectionally synchronized with my external hard disk?

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• How to disable or tune filesystem cache sharing for OpenVZ?

  - by gertvdijk

  For OpenVZ, an example of container-based virtualization, it seems that host and all guests are sharing the filesystem cache. This sounds paradoxical when talking about virtualization, but this is actually a feature of OpenVZ. It makes sense too. Because only one kernel is running, it's possible to benefit from sharing the same pages of filesystem cache in memory. And while it sounds beneficial, I think a set up here actually suffers in performance from it. Here's why I think why: my machines aren't actually sharing any files on disk so I can't benefit from this feature in OpenVZ. Several OpenVZ machines are running MySQL with MyISAM tables. MyISAM relies on the system's filesystem cache for caching of data files, unlike InnoDB's buffer pool. Also some virtual machines are known to do heavy and large I/O operations on the same filesystem in the host. For example, when running cat *.MYD > /dev/null on some large database in one machine, I saw the filesystem cache lowering in another, monitored by htop. This essentially flushes all the useful filesystem cache in guests (FIFO) and so it flushes the MySQL caches in the guests. Now users are complaining that MySQL is very slow. And it is. Some simple SELECT queries take several seconds on times disk I/O is heavily used by other machines. So, simply put: Is there a way to avoid filesystem cache being wiped out by other virtual machines in container-based virtualization? Some thoughts: Choosing algorithm for flushing filesystem cache in the kernel. (possible? how?) Reserving a certain amount of pages for a single VM. (seems no option for filesystem cache type of pages that reading man vzctl) Will running MySQL on another filesystem get me anywhere? If not, I think my alternatives are: Use KVM for MySQL-MyISAM running VMs. KVM actually assigns memory to the VM and does not allow swapping out caches unless using a balloon driver. Move to InnoDB and tune the buffer pools, dirty pages, etc. This is now considered to be 'nice to have' on the long-term as not everyone responsible for administration of the system understands InnoDB. more suggestions welcome. System software: Proxmox (now 1.9, could be upgraded to 2.x). One big LV assigned for the VMs.

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• High CPU usage - symptoms moving from server to server after bouncing

  - by grt3kl

  First off, I apologize if I didn't include enough information to properly troubleshoot this issue. This sort of thing isn't my specialty, so it is a learning process. If there's something I need to provide, please let me know and I'll be happy to do what I can. The images associated with my question are at the bottom of this post. We are dealing with a clustered environment of four WebLogic 9.2 Java application servers. The cluster utilizes a round-robin load algorithm. Other details include: Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_12-b04) BEA JRockit(R) (build R27.4.0-90_CR352234-91983-1.5.0_12-20071115-1605-linux-x86_64, compiled mode) Basically, I started looking at the servers' performance because our customers are seeing lots of lag at various times of the day. Our servers should easily handle the loads they are given, so it's not clear what's going on. Using HP Performance Manager, I generated some graphs that indicate that the CPU usage is completely out of whack. It seems that, at any given point, one or more of the servers has a CPU utilization of over 50%. I know this isn't particularly high, but I would say it is a red flag based on the CPU utilization of the other servers in the WebLogic cluster. Interesting things to note: The high CPU utilization was occurring only on server02 for several weeks. The server crashed (extremely rare; we are not sure if it's related to this) and upon starting it back up, the CPU utilization was normal on all 4 servers. We restarted all 4 managed servers and the application server (on server01) yesterday, on 2/28. As you can see, server03 and server04 picked up the behavior that was seen on server02 before. The CPU utilization is a Java process owned by the application user (appown). The number of transactions is consistent across all servers. It doesn't seem like any one server is actually handling more than another. If anyone has any ideas or can at least point me in the right direction, that would be great. Again, please let me know if there is any additional information I should post. Thanks!

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• C#: System.Lazy&lt;T&gt; and the Singleton Design Pattern

  - by James Michael Hare

  So we've all coded a Singleton at one time or another.  It's a really simple pattern and can be a slightly more elegant alternative to global variables.  Make no mistake, Singletons can be abused and are often over-used -- but occasionally you find a Singleton is the most elegant solution. For those of you not familiar with a Singleton, the basic Design Pattern is that a Singleton class is one where there is only ever one instance of the class created.  This means that constructors must be private to avoid users creating their own instances, and a static property (or method in languages without properties) is defined that returns a single static instance. 1: public class Singleton 2: { 3: // the single instance is defined in a static field 4: private static readonly Singleton _instance = new Singleton(); 5:  6: // constructor private so users can't instantiate on their own 7: private Singleton() 8: { 9: } 10:  11: // read-only property that returns the static field 12: public static Singleton Instance 13: { 14: get 15: { 16: return _instance; 17: } 18: } 19: } This is the most basic singleton, notice the key features: Static readonly field that contains the one and only instance. Constructor is private so it can only be called by the class itself. Static property that returns the single instance. Looks like it satisfies, right?  There's just one (potential) problem.  C# gives you no guarantee of when the static field _instance will be created.  This is because the C# standard simply states that classes (which are marked in the IL as BeforeFieldInit) can have their static fields initialized any time before the field is accessed.  This means that they may be initialized on first use, they may be initialized at some other time before, you can't be sure when. So what if you want to guarantee your instance is truly lazy.  That is, that it is only created on first call to Instance?  Well, there's a few ways to do this.  First we'll show the old ways, and then talk about how .Net 4.0's new System.Lazy<T> type can help make the lazy-Singleton cleaner. Obviously, we could take on the lazy construction ourselves, but being that our Singleton may be accessed by many different threads, we'd need to lock it down. 1: public class LazySingleton1 2: { 3: // lock for thread-safety laziness 4: private static readonly object _mutex = new object(); 5:  6: // static field to hold single instance 7: private static LazySingleton1 _instance = null; 8:  9: // property that does some locking and then creates on first call 10: public static LazySingleton1 Instance 11: { 12: get 13: { 14: if (_instance == null) 15: { 16: lock (_mutex) 17: { 18: if (_instance == null) 19: { 20: _instance = new LazySingleton1(); 21: } 22: } 23: } 24:  25: return _instance; 26: } 27: } 28:  29: private LazySingleton1() 30: { 31: } 32: } This is a standard double-check algorithm so that you don't lock if the instance has already been created.  However, because it's possible two threads can go through the first if at the same time the first time back in, you need to check again after the lock is acquired to avoid creating two instances. Pretty straightforward, but ugly as all heck.  Well, you could also take advantage of the C# standard's BeforeFieldInit and define your class with a static constructor.  It need not have a body, just the presence of the static constructor will remove the BeforeFieldInit attribute on the class and guarantee that no fields are initialized until the first static field, property, or method is called.   1: public class LazySingleton2 2: { 3: // because of the static constructor, this won't get created until first use 4: private static readonly LazySingleton2 _instance = new LazySingleton2(); 5:  6: // Returns the singleton instance using lazy-instantiation 7: public static LazySingleton2 Instance 8: { 9: get { return _instance; } 10: } 11:  12: // private to prevent direct instantiation 13: private LazySingleton2() 14: { 15: } 16:  17: // removes BeforeFieldInit on class so static fields not 18: // initialized before they are used 19: static LazySingleton2() 20: { 21: } 22: } Now, while this works perfectly, I hate it.  Why?  Because it's relying on a non-obvious trick of the IL to guarantee laziness.  Just looking at this code, you'd have no idea that it's doing what it's doing.  Worse yet, you may decide that the empty static constructor serves no purpose and delete it (which removes your lazy guarantee).  Worse-worse yet, they may alter the rules around BeforeFieldInit in the future which could change this. So, what do I propose instead?  .Net 4.0 adds the System.Lazy type which guarantees thread-safe lazy-construction.  Using System.Lazy<T>, we get: 1: public class LazySingleton3 2: { 3: // static holder for instance, need to use lambda to construct since constructor private 4: private static readonly Lazy<LazySingleton3> _instance 5: = new Lazy<LazySingleton3>(() => new LazySingleton3()); 6:  7: // private to prevent direct instantiation. 8: private LazySingleton3() 9: { 10: } 11:  12: // accessor for instance 13: public static LazySingleton3 Instance 14: { 15: get 16: { 17: return _instance.Value; 18: } 19: } 20: } Note, you need your lambda to call the private constructor as Lazy's default constructor can only call public constructors of the type passed in (which we can't have by definition of a Singleton).  But, because the lambda is defined inside our type, it has access to the private members so it's perfect. Note how the Lazy<T> makes it obvious what you're doing (lazy construction), instead of relying on an IL generation side-effect.  This way, it's more maintainable.  Lazy<T> has many other uses as well, obviously, but I really love how elegant and readable it makes the lazy Singleton.

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• SQL SERVER – Service Broker and CAP_CPU_PERCENT – Limiting SQL Server Instances to CPU Usage

  - by pinaldave

  I have mentioned several times on this blog that the best part of blogging is the questions I receive from readers. They are often very interesting. The questions from readers give me a good idea what other readers might be thinking as well. After reading my earlier article Simple Example to Configure Resource Governor – Introduction to Resource Governor – I received an email from a reader and we exchanged a few emails. After exchanging emails we both figured out what is going on. It was indeed interesting and reader suggested to that I should blog about it.  I asked for permission to publish his name but he does not like the attention so we will just call him Jeff. I have converted our emails into chat for easy consumption. Jeff: Your script does not work at all. I think either there is a bug in SQL Server. Pinal: Would you please explain in detail? Jeff: Your code does not limit the CPU usage? Pinal: How did you measure it? Jeff: Well, we have third party tools for it but let us say I have limited the resources for Reporting Services and used your script described in your blog. After that I ran only reporting service workload the CPU is still used more than 100% and it is not limited to 30% as described in your script. Clearly something is wrong somewhere. Pinal: Did you say you ONLY ran reporting server load? Jeff: Yeah, to validate I ran ONLY reporting server load and CPU did not throttle at 30% as per your script. Pinal: Oh! I get it here is the answer - CAP_CPU_PERCENT = 30. Use it. Jeff: What is that, I think your earlier script says it will throttle the Reporting Service workload and Application/OLTP workload and balance it. Pinal: Exactly, that is correct. Jeff: You need to write more in email buddy! Just like your blogs, your answers do not make sense! No Offense! Pinal: Hmm…feedback well taken. Let me try again. In SQL Server 2012 there are a few enhancements with regards to SQL Server Resource Governor. One of the enhancement is how the resources are allocated. Let me explain you with examples. Configuration: [Read Earlier Post] Reporting Workload: MIN_CPU_PERCENT=0, MAX_CPU_PERCENT=30 Application/OLTP Workload: MIN_CPU_PERCENT=50, MAX_CPU_PERCENT=100 Example 1: If there is only Reporting Workload on the server: SQL Server will not limit usage of CPU to only 30% workload but SQL Server instance will use all available CPU (if needed). In another word in this scenario it will use more than 30% CPU. Example 2: If there is Reproting Workload and heavy Application/OLTP workload: SQL Server will allocate a maximum of 30% CPU resources to Reporting Workload and allocate remaining resources to heavy application/OLTP workload. The reason for this enhancement is for better utilization of the resources. Let us think, if there is only single workload, which we have limited to max CPU usage to 30%. The other unused available CPU resources is now wasted. In this situation SQL Server allows the workload to use more than 30% resources leading to overall improved/optimized performance. However, in the case of multiple workload where lots of resources are needed the limits specified in MAX_CPU_PERCENT are acknowledged. Example 3: If there is a situation where the max CPU workload has to be enforced: This is a very interesting scenario, in the case when the max CPU workload has to be enforced irrespective of the workload and enhanced algorithm, the keyword CAP_CPU_PERCENT is essential. It specifies a hard cap on the CPU bandwidth that all requests in the resource pool will receive. It will never let CPU usage for reporting workload to go over 30% in our case. You can use the key word as follows: -- Creating Resource Pool for Report Server CREATE RESOURCE POOL ReportServerPool WITH ( MIN_CPU_PERCENT=0, MAX_CPU_PERCENT=30, CAP_CPU_PERCENT=40, MIN_MEMORY_PERCENT=0, MAX_MEMORY_PERCENT=30) GO Notice that there is MAX_CPU_PERCENT=30 and CAP_CPU_PERCENT=40, what it means is that when SQL Server Instance is under heavy load under different workload it will use the maximum CPU at 30%. However, when the SQL Server instance is not under workload it will go over the 30% limit. However, as CAP_CPU_PERCENT is set to 40, it will not go over 40% in any case by limiting the usage of CPU. CAP_CPU_PERCENT puts a hard limit on the resources usage by workload. Jeff: Nice Pinal, you should blog about it. [A day passes by] Pinal: Jeff, it is done! Click here to read it. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Service Broker

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• NET Math Libraries

  - by JoshReuben

  NET Mathematical Libraries   .NET Builder for Matlab The MathWorks Inc. - http://www.mathworks.com/products/netbuilder/ MATLAB Builder NE generates MATLAB based .NET and COM components royalty-free deployment creates the components by encrypting MATLAB functions and generating either a .NET or COM wrapper around them. .NET/Link for Mathematica www.wolfram.com a product that 2-way integrates Mathematica and Microsoft's .NET platform call .NET from Mathematica - use arbitrary .NET types directly from the Mathematica language. use and control the Mathematica kernel from a .NET program. turns Mathematica into a scripting shell to leverage the computational services of Mathematica. write custom front ends for Mathematica or use Mathematica as a computational engine for another program comes with full source code. Leverages MathLink - a Wolfram Research's protocol for sending data and commands back and forth between Mathematica and other programs. .NET/Link abstracts the low-level details of the MathLink C API. Extreme Optimization http://www.extremeoptimization.com/ a collection of general-purpose mathematical and statistical classes built for the.NET framework. It combines a math library, a vector and matrix library, and a statistics library in one package. download the trial of version 4.0 to try it out. Multi-core ready - Full support for Task Parallel Library features including cancellation. Broad base of algorithms covering a wide range of numerical techniques, including: linear algebra (BLAS and LAPACK routines), numerical analysis (integration and differentiation), equation solvers. Mathematics leverages parallelism using .NET 4.0's Task Parallel Library. Basic math: Complex numbers, 'special functions' like Gamma and Bessel functions, numerical differentiation. Solving equations: Solve equations in one variable, or solve systems of linear or nonlinear equations. Curve fitting: Linear and nonlinear curve fitting, cubic splines, polynomials, orthogonal polynomials. Optimization: find the minimum or maximum of a function in one or more variables, linear programming and mixed integer programming. Numerical integration: Compute integrals over finite or infinite intervals, over 2D and higher dimensional regions. Integrate systems of ordinary differential equations (ODE's). Fast Fourier Transforms: 1D and 2D FFT's using managed or fast native code (32 and 64 bit) BigInteger, BigRational, and BigFloat: Perform operations with arbitrary precision. Vector and Matrix Library Real and complex vectors and matrices. Single and double precision for elements. Structured matrix types: including triangular, symmetrical and band matrices. Sparse matrices. Matrix factorizations: LU decomposition, QR decomposition, singular value decomposition, Cholesky decomposition, eigenvalue decomposition. Portability and performance: Calculations can be done in 100% managed code, or in hand-optimized processor-specific native code (32 and 64 bit). Statistics Data manipulation: Sort and filter data, process missing values, remove outliers, etc. Supports .NET data binding. Statistical Models: Simple, multiple, nonlinear, logistic, Poisson regression. Generalized Linear Models. One and two-way ANOVA. Hypothesis Tests: 12 14 hypothesis tests, including the z-test, t-test, F-test, runs test, and more advanced tests, such as the Anderson-Darling test for normality, one and two-sample Kolmogorov-Smirnov test, and Levene's test for homogeneity of variances. Multivariate Statistics: K-means cluster analysis, hierarchical cluster analysis, principal component analysis (PCA), multivariate probability distributions. Statistical Distributions: 25 29 continuous and discrete statistical distributions, including uniform, Poisson, normal, lognormal, Weibull and Gumbel (extreme value) distributions. Random numbers: Random variates from any distribution, 4 high-quality random number generators, low discrepancy sequences, shufflers. New in version 4.0 (November, 2010) Support for .NET Framework Version 4.0 and Visual Studio 2010 TPL Parallellized – multicore ready sparse linear program solver - can solve problems with more than 1 million variables. Mixed integer linear programming using a branch and bound algorithm. special functions: hypergeometric, Riemann zeta, elliptic integrals, Frensel functions, Dawson's integral. Full set of window functions for FFT's. Product  Price Update subscription Single Developer License $999  $399  Team License (3 developers) $1999  $799  Department License (8 developers) $3999  $1599  Site License (Unlimited developers in one physical location) $7999  $3199    NMath http://www.centerspace.net .NET math and statistics libraries matrix and vector classes random number generators Fast Fourier Transforms (FFTs) numerical integration linear programming linear regression curve and surface fitting optimization hypothesis tests analysis of variance (ANOVA) probability distributions principal component analysis cluster analysis built on the Intel Math Kernel Library (MKL), which contains highly-optimized, extensively-threaded versions of BLAS (Basic Linear Algebra Subroutines) and LAPACK (Linear Algebra PACKage). Product  Price Update subscription Single Developer License $1295 $388 Team License (5 developers) $5180 $1554   DotNumerics http://www.dotnumerics.com/NumericalLibraries/Default.aspx free DotNumerics is a website dedicated to numerical computing for .NET that includes a C# Numerical Library for .NET containing algorithms for Linear Algebra, Differential Equations and Optimization problems. The Linear Algebra library includes CSLapack, CSBlas and CSEispack, ports from Fortran to C# of LAPACK, BLAS and EISPACK, respectively. Linear Algebra (CSLapack, CSBlas and CSEispack). Systems of linear equations, eigenvalue problems, least-squares solutions of linear systems and singular value problems. Differential Equations. Initial-value problem for nonstiff and stiff ordinary differential equations ODEs (explicit Runge-Kutta, implicit Runge-Kutta, Gear's BDF and Adams-Moulton). Optimization. Unconstrained and bounded constrained optimization of multivariate functions (L-BFGS-B, Truncated Newton and Simplex methods).   Math.NET Numerics http://numerics.mathdotnet.com/ free an open source numerical library - includes special functions, linear algebra, probability models, random numbers, interpolation, integral transforms. A merger of dnAnalytics with Math.NET Iridium in addition to a purely managed implementation will also support native hardware optimization. constants & special functions complex type support real and complex, dense and sparse linear algebra (with LU, QR, eigenvalues, ... decompositions) non-uniform probability distributions, multivariate distributions, sample generation alternative uniform random number generators descriptive statistics, including order statistics various interpolation methods, including barycentric approaches and splines numerical function integration (quadrature) routines integral transforms, like fourier transform (FFT) with arbitrary lengths support, and hartley spectral-space aware sequence manipulation (signal processing) combinatorics, polynomials, quaternions, basic number theory. parallelized where appropriate, to leverage multi-core and multi-processor systems fully managed or (if available) using native libraries (Intel MKL, ACMS, CUDA, FFTW) provides a native facade for F# developers

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• Big Data – What is Big Data – 3 Vs of Big Data – Volume, Velocity and Variety – Day 2 of 21

  - by Pinal Dave

  Data is forever. Think about it – it is indeed true. Are you using any application as it is which was built 10 years ago? Are you using any piece of hardware which was built 10 years ago? The answer is most certainly No. However, if I ask you – are you using any data which were captured 50 years ago, the answer is most certainly Yes. For example, look at the history of our nation. I am from India and we have documented history which goes back as over 1000s of year. Well, just look at our birthday data – atleast we are using it till today. Data never gets old and it is going to stay there forever.  Application which interprets and analysis data got changed but the data remained in its purest format in most cases. As organizations have grown the data associated with them also grew exponentially and today there are lots of complexity to their data. Most of the big organizations have data in multiple applications and in different formats. The data is also spread out so much that it is hard to categorize with a single algorithm or logic. The mobile revolution which we are experimenting right now has completely changed how we capture the data and build intelligent systems.  Big organizations are indeed facing challenges to keep all the data on a platform which give them a  single consistent view of their data. This unique challenge to make sense of all the data coming in from different sources and deriving the useful actionable information out of is the revolution Big Data world is facing. Defining Big Data The 3Vs that define Big Data are Variety, Velocity and Volume. Volume We currently see the exponential growth in the data storage as the data is now more than text data. We can find data in the format of videos, musics and large images on our social media channels. It is very common to have Terabytes and Petabytes of the storage system for enterprises. As the database grows the applications and architecture built to support the data needs to be reevaluated quite often. Sometimes the same data is re-evaluated with multiple angles and even though the original data is the same the new found intelligence creates explosion of the data. The big volume indeed represents Big Data. Velocity The data growth and social media explosion have changed how we look at the data. There was a time when we used to believe that data of yesterday is recent. The matter of the fact newspapers is still following that logic. However, news channels and radios have changed how fast we receive the news. Today, people reply on social media to update them with the latest happening. On social media sometimes a few seconds old messages (a tweet, status updates etc.) is not something interests users. They often discard old messages and pay attention to recent updates. The data movement is now almost real time and the update window has reduced to fractions of the seconds. This high velocity data represent Big Data. Variety Data can be stored in multiple format. For example database, excel, csv, access or for the matter of the fact, it can be stored in a simple text file. Sometimes the data is not even in the traditional format as we assume, it may be in the form of video, SMS, pdf or something we might have not thought about it. It is the need of the organization to arrange it and make it meaningful. It will be easy to do so if we have data in the same format, however it is not the case most of the time. The real world have data in many different formats and that is the challenge we need to overcome with the Big Data. This variety of the data represent  represent Big Data. Big Data in Simple Words Big Data is not just about lots of data, it is actually a concept providing an opportunity to find new insight into your existing data as well guidelines to capture and analysis your future data. It makes any business more agile and robust so it can adapt and overcome business challenges. Tomorrow In tomorrow’s blog post we will try to answer discuss Evolution of Big Data. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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