Search Results

Search found 3661 results on 147 pages for 'overload resolution'.

Page 135/147 | < Previous Page | 131 132 133 134 135 136 137 138 139 140 141 142  | Next Page >

  • Need Windows XP VGA driver for i3 Haswell

    - by AFH
    Background: I have recently upgraded my hardware because the previous Pentium system started failing to the point that it would not run long enough to boot. It was obviously a hardware fault, but I had no way of knowing whether it was in the motherboard, CPU or memory. Not all the components were now available, so I decided to replace all three. In order to get some benefit from the expenditure, I though I would put in faster components, and for future-proofing went for recently released ones: MSI Z87-G41-PCMate and Intel i3-4130 with 4400 HD graphics. The system performs excellently with Ubuntu 13.10, so I know there are no hardware problems, but I need to continue running XP because it runs several thousand pounds (UK) worth of software, which meets my needs more than adequately: in some cases there is no longer support for later Windows releases, and in most others an expensive and to me unnecessary upgrade is required. Problem: The motherboard specifications claim Windows XP support for the live driver update utility, which misled me into believing that XP drivers were available. Not true: Intel have apparently refused to provide XP drivers for Haswell chips. The update program runs on XP, but finds no suitable Intel drivers. The system is more or less running on the default fail-safe VGA driver, but DirectX will not load, which stops a number of my applications from running. I have been trawling the internet for a month now, but I have not found a graphics driver which will load successfully: all show "This device cannot start. (code 10)". I don't need HDMI support: my monitor is 1280x1024 and connected through the VGA port, so all I need is a driver which will handle this resolution well enough to support DirectX. Has anyone found a driver which will do this? Please don't reply with information found from internet searches, unless you have actually solved this problem: be assured that I have been all round the houses looking at solutions which others have reported as working, but none of them does for me. Incidentally, I did find an Intel HD sound driver which XP accepts (winxp_145111.exe from Intel), though without connecting to an HDMI port on a TV or sound system I have no idea if it works in practice. However, the graphics section of the same driver fails, like all the others I've tried.

    Read the article

  • Convert mkv/h264 video so it can be played on a "mid-range" Sony Ericsson phone. (using Ubuntu).

    - by Johan
    Hi As a little experiment I thinking of converting some video/movies/tv-series into a format that could be playable on my K850, but to be a little bit more generic in this question let's say "mid range Sony Ericsson" phone since they all more or less behave the same and has the same screen resolution (240 x 320). I am looking for command line based tools (for Ubuntu), since I am thinking about writing a "convert and move" script later if it is successful. A lot of the video I have is encoded in mkv/h264, but since that is not supported by the phone I guess that I need to convert it into some mp4/mpeg4 low quality video. After some googling it seems like a good candidate for the job is ffmpeg, but that seems to be a very versatile tool with a lot of magic tricks. Am I on the right track? And if so how do I use ffmpeg to do this? Thanks Johan Update: After plating a little bit with ffmeg I noticed that it only uses 1 of my 4 cores, so the transcoding takes forever. I found a arg called -threads but that did not change much, maybe I got it wrong. I also found that something like this plays in the phone. ffmpeg -i Mythbusters\ S1D1_1.mkv -threads 4 -t 180 -vcodec mpeg4 -r 15 -s 320x240 Mythbusters\ S1D1_1_mini.mp4 It was possible to use 3gp/h263, but the quality was really useless. ffmpeg -i Mythbusters\ S1D1_1.mkv -t 180 -vcodec h263 -acodec libfaac -s cif Mythbusters\ S1D1_1_cif.3gp And it seems like mp4/h264 is also possible and the result is ok, thanks to this question, this one seem to use more than one core as well so it was a little bit faster for me. ffmpeg -i Mythbusters_S1D1_1.mkv -t 180 -acodec libfaac -ab 60k -s 320x240 -vcodec libx264 -b 500k -flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -flags2 +mixed_refs -me_method umh -subq 6 -trellis 1 -refs 5 -coder 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -bt 500k -maxrate 768k -bufsize 2M -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -level 13 -threads 0 -f mp4 Mythbusters_S1D1_1_qvga.mp4 Update: I have tried to use HandBrakeCLI and it is no problem creating a new file that seem to be the same as the one created with ffmpeg with something like this. HandBrakeCLI -i Mythbusters_S1D1_1.mkv --size 100 -E faac -B 60 --maxHeight 240 -r 15 -e x264 -o Mythbusters_S1D1_1_hand.mp4 But that one did not play in the phone... I found this in the official manual: If you transfer video clips using another program than Media Go™, we recommend that you select H.264 Baseline profile video, up to QVGA at 30 fps, VBR 384 kbps (max 768 kps) with AAC+ audio at 128 kbps (max 255 kbps), 48 kHz and stereo audio in mp4 file format. So the idea to use H264 seems to be correct.

    Read the article

  • Intermittent Disconnection of Client Computers from Domain Server

    - by dilip nagle
    The Background: I have Windows 2008 server Enterprise Version with 25 user cal licences. It has a domain and all users and a network shared HP printer in it. The Server has two network cards and both these cards as well as all client machines are on IP addressing scheme of 192.168.1.* with subnetmask 255.255.255.0. Of the two network cards viz. 192.168.1.231 and 192.168.1.233, only 192.168.1.231 is registered with DNS. In 192.168.1.233(i.e. 2nd network card) has default getway as 192.168.1.231 and dns address as 192.168.1.231. The Server has three hard disks with capacities as 500gb, 500gb and 1TB and are partitioned as (C,D,E), (F,G) and (K) with partition K having all user data into various Shared Folders. Each of these folders(On Partition K), are mapped onto each user's computer as per the right of access given to them. The Problem: The Server was installed about 6 months ago and till date not even once, the Server has Hung or has given any problem. All the Clients computers are able to run the web based software from their computers via ip address, e.g. http://192.168.1.231/webERP/default.aspx. However, occassionally, when any client computer tries to browse network mappings, it hangs. Again, there is no fixed pattern. This may happen after running smoothly for say 3 days. On each Client's machine, the network settings are as follows: IP Address: 192.168.1.* where * is 1,2,3 .... Sunnetmask: 255.255.255.0 defauly getway: 192.168.1.231 Which is a server card and DNS address. preferred DNS Server: 192.168.1.231 In Advanced Tab under Wins: LMHostLookup is Unticked and default is radio buttoned. Ideally, I would have loved to have Disabled NETBIOS over TCP/IP but some network printers do not get accessed if this option is enabled(ie. Radio Buttoned). Bacause Disabling Netbios will drastically reduce traffic of NETBIOS broadcasting to all the computers on the net to do naming resolution. On Server, I have WINs Running which I have Scavanged Records, verified Database Integrity etc, removed Tombstoned Records etc. The Critical Errors shown only once a day when the server is statred are 4224(WINS) and 12923 - Server Licencing failed to Update DNS Record. I fail to understand as why do client machines HANG when they try to browse mapped network shared folders on K Drive. Kindly Advice

    Read the article

  • Windows Setup could not configure Windows to run on this computer's hardware

    - by Hello71
    The whole installation goes smoothly up to the point of "Completing installation ...". The monitor changes resolution, after which a standard dialog box pops up saying Windows Setup could not configure Windows to run on this computer's hardware Then, in a few seconds, the whole machine powers down. Trying to restart produces the message: STOP: c000021a {Fatal System Error} 0x00000000 (0xc0000001 0x00100448) OR it boots into Setup and comes up with the message: Windows Setup encountered an unexpected error... (This is not the actual error, just paraphrasing) I tried using the OEM restore instead of a regular install, but it fails with the same error. (Even though it worked before...) General specs: HP Pavilion Elite e9262f Intel Core i5-750 Processor ATI Radeon HD 4650 Hitachi HDT721010SLA360 ATA Device 6GB DDR3 RAM SuperMulti DVD Burner with LightScribe Some built-in Wi-Fi module http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01916917 I've tried disconnecting the wireless card and disabling the built-in Ethernet and Firewire via the BIOS, and replacing the wireless keyboard and mouse with wired USB ones. Didn't work. I've also tried changing the SATA controller settings in the BIOS to RAID, AHCI, and IDE, reinstalling each time I changed. Still not working. I think the reason why it is showing the Fatal System Error is because it didn't finish installing before it errored out and shut down, so the system is left in an inconsistent state. I've tried 3 different copies (including the OEM restore) of Windows 7 now, and they're all failing at the same point, with the same error message. I've tried to install Windows 7 maybe 10 times already, with the exact same error message at the exact same location. Hm... Interestingly, the 32-bit version of Windows 7 works, but the 64-bit version doesn't. Perhaps it was a badly burned disk? Reburning the 64-bit version still comes up with the same error. Here's a picture of the side of the case that clearly says it came with Windows 7 64-bit, along with the model number and CPU. sudo fdisk -l: Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0009896f Device Boot Start End Blocks Id System /dev/sda1 * 1 13 104391 7 HPFS/NTFS /dev/sda2 14 94119 755906445 7 HPFS/NTFS /dev/sda3 119922 121602 13492224 7 HPFS/NTFS /dev/sda4 94120 119922 207257740+ 5 Extended /dev/sda5 119527 119922 3170769 82 Linux swap / Solaris /dev/sda6 107174 119526 99225441 83 Linux /dev/sda7 94120 107173 104856192 7 HPFS/NTFS Partition table entries are not in disk order

    Read the article

  • Snow Leopard can see Windows shares in Finder but can't connect

    - by Randy Miller
    I have an iMac with the latest version of Snow Leopard on it. I have a NAS drive and a Windows machine that both show up in the Finder's 'Shared' section. However, if I click on them, Finder says "Connection Failed". Clicking on 'Connect As...' gives an error dialog that says "The server 'blah' may not exist or it is unavailable at this time." Points of interest: All machines are receiving their IP/DNS info from the router using DHCP. I have a Mac Mini on the same network that connects to the NAS drive and windows machine perfectly with no config (i.e. worked out of the box). Both Macs are on the same version of Snow Leopard. There is no password required to access the NAS share. I've never setup a WINS server on any machines and all machines are using 'workgroup' by default. I've tried putting "workgroup" in the Mac's workgroup entry and have tried leaving it blank, neither solves the problem. Here are some things I have tried: Finder-Connect To Server: smb:///share. This works, but by name does not. Terminal-mount_smbfs //@/share share. This also works by ip, but not be name, resulting in "mount_smbfs: server connection failed: No route to host". If I put the IP address of the NAS in the WINS server entry in the Mac's network setup, I can connect by name. It obviously seems to be a name resolution error, but I can't figure out why. The only thing that has changed since it used to work is that I got a new router that now gives out DHCP (all machines are dhcp clients) addresses of 192.168.x.x, but used to be 10.0.x.x. I've grep'd through everything that might have saved that old address, but can't find anything. It's also worth noting that the second Mac (the one that connects successfully) was added to the network after the router change. Please let me know if there are additional points of information needed to troubleshoot this further. Thanks, Randy

    Read the article

  • Internet Working, Browsing Not.

    - by jeffreypriebe
    I have a very odd problem that I can't resolve. I am connected to the internet, but my browsing doesn't work. I don't mean a web browser - I mean browsing. Firefox, Chrome, Curl all fail to successfully connect to an HTTP address. However existing connections, e.g. to mail in Outlook (Exchange Server and also IMAP server) continue to work. Also, the internet is on, I can confirm both from my machine (other ports / connections) as well as from any other computer connected to the same network. Additionally, it appears to be HTTP, not simple a port issue as HTTP over port 8443 (Tortoise SVN if you must know - running over HTTP not over SVN) also fails. I am using Windows Vista SP2 (build 6002). It seems to "creep up" in that after running the computer for a few hours it will fail. (No found way to systematically reproduce the problem.) Additionally, it seems to be more prone on days where the internet connection is flaky already (not sure why the internet is flaky, just is, lot's of failed browsing requests and have to retry/reload often). What I have tried (when the problem arises) - none have yielded any resolution: Resetting the network connection (dis-connect, re-connect) Disable/re-enable the network adapter Double-checked the ip settings Double-checked the HOSTS file. Note: DNS continues to work (both new and cached responses to DNS queries). (Thanks for the suggestion Daniel and antenore.) Checked the routing tables (ip4 only as ipv6 is beyond my understanding) resetting all involved hardware (routers and modems) Close and reopen browsers Looked for malware interference: Run HijackThis Looked for suspicious processes using SysInternals procexp. Looked for explorer hijacks, lsa provider interference, winsock provider interference using SysInternals Autoruns. Run a complete anti-virus scan. Reviewed the output of a netstat -onab to see if there were stuck ports open or unusual processes running somewhere The only thing that works is to do a full reboot. That works 100% of the time to restore browsing. What else can I try to nail down the problem?

    Read the article

  • PDF Corruption When Sending with Microsoft Products

    - by Winner
    I have the same PDF corruption problem in two different offices that I am the tech support for. Office 1: Started in the middle of December. PDF received from outside the office and is viewable with no problems. I have no control over how it is created. If it is forwarded to anyone else, the PDF is corrupted. I have forwarded it to multiple people in the office. I have tried viewing with Reader 8, 9, Sumatra and Fox IT. I have tried forwarding to Gmail and their viewer says it is corrupted. If I save the PDF and create a new email, it will be corrupted when sent using Outlook 2003, Outlook 2007, Microsoft Live Mail and Outlook Express. If I create the email using Thunderbird 3, Gmail or the webclient Iclient for IPSwitch IMail it will not be corrupted. I have confirmed the same results when using our IMail SMTP and also Using Gmail as the SMTP server. To be clear, if I created in Thunderbird, Gmail or Iclient and received on any of the MS products, it will be viewable. This office receives PDFs daily from multiple sources. There is only a small subset that are having this problem. So far they problem PDFs are from two different companies they deal with, but not all of the PDFs are bad. Office 2: PDFs are created by a management system. I'm not sure what engine is used to create them. Same exact same issues. At both offices, I noticed that the file size is wrong. One small PDF the proper file size is 12kb for the PDF when it's viewable, when it shows up corrupted it is only 8kb. We handle the email for both offices. Both are POP servers, not Exchange. IMail was updated after these issues start. I have tried different SMTP servers and it still seems to happen only when using Microsoft products to send. Anyone else having problems with PDFs getting corrupted? Any ideas how to find out a resolution?

    Read the article

  • Tomcat and IIS 7 both on different ip's and different ports

    - by n00b
    I have Tomcat and IIS 7 installed together on a Windows 2008 server. The machine has two IPs (134.133.1.1 and 134.133.2.2). I want Tomcat to handle 134.133.1.1, on port 80, and IIS to handle both 134.133.2.2, on port 80 AND 134.133.1.1, on port 443, but can't seem to get the last two together (I can get one or the other by themselves on IIS, along with the first IP address on Tomcat). I have configured Tomcat to successfully listen to ip 134.133.1.1, on port 80 with this configuration; <Connector port="80" protocol="HTTP/1.1" address="134.133.1.1" connectionTimeout="20000" redirectPort="8443" /> I also have a site configured in IIS bound to ip 134.133.1.1, on port 443 (SSL). When I turn on IIS, after Tomcat, I can reach both 134.133.1.1:80 (Tomcat) and 134.133.1.1:443 (IIS) successfully (as desired). The problem now comes when I want to introduce a new site via IIS, at the new ip address. In IIS I have setup a new site at IP 134.133.2.2, port 80. I can not start the site. The event log shows this error; Unable to bind to the underlying transport for [::]:80. The IP Listen-Only list may contain a reference to an interface which may not exist on this machine. The data field contains the error number. I think this is because IIS 7 tries to listen to port 80 on all IPs, and it cant because Tomcat is taking port 80 for 134.133.1.1. From reading, the resolution is to specify the IP address you want IIS to bind on port 80. The problem is, when I add 134.133.2.2 to the iplisten list, then I get a 404 when I try navigating to 134.133.1.1:443. I assume this is because IIS is no longer listening to ANY port on 134.133.1.1. How do I resolve this such that IIS will return both sites? EDIT: Per request my IIS binding for site A is 134.133.2.2 on port 80 (http) and 134.133.2.2 on port 443. For site B in IIS, the binding is 134.133.1.1 on port 443 (https). Note the IPs in this example are just for example purposes, but consistent with my setup.

    Read the article

  • DVD playback with Windows Media Player 11 works fine, but when copied to HDD and then played back, t

    - by stakx
    I have several DVDs with short documentaries on it. Since the notebook I'm using (a Dell Latitude E6400) has only one DVD drive, and I might play back those short movies very often, I thought of copying them to the HDD and playing them back from there. However, I've run into a problem, namely stuttering audio. Problem description: When I play back these movies directly from DVD (with Windows Media Player 11 under Windows Vista), everything works fine. Smooth video, no significant audio problems (only the occasional click). But as soon as I copy any of these DVDs to the HDD and try to play them back from there (e.g. using the wmpdvd://drive/title/chapter?contentdir=path protocol, I get stuttering audio — audio playback sounds like a machine gun for a third of a second or so, approx. every 8 seconds. I have tried converting the VOB files from the DVD to another format (ie. ripping), but that resulted in a noticeable downgrade of picture quality. Therefore I thought it best to keep the files in their original format, if possible. Still, I suspect that the stuttering audio is due to some (de-)muxing problem, and that changing the file format might help. (After all, video playback is fine; therefore I don't think that the hardware is too slow for playback.) Only thing is, I don't know how to convert the VOB files to another Windows Media Player-compatible format without quality loss. I hope someone can help me, or give me further pointers on things I could try out to get HDD playback to work without the problem described. Some things I've tried so far, without any success: VOB2MPG, in order to convert the .vob file to a .mpg file. But that changes only the A/V container, not the content. No re-encoding takes place at all. Re-encoding with MPlayer/MEncoder. Lots of quality loss there, and I frankly haven't got the time to test all possible settings combinations available. Disabling all plug-ins, equalizers, etc. in Windows Media Player. Disabling all hardware acceleration on the audio playback device. Further info on the VOB files I'm trying to playback: The video format is MPEG ES, PAL 720x576 pixels @ 24/25 frames per second. The sound stream is uncompressed PCM, 16-bit stereo @ 48kHz. (Might it help if I somehow re-encoded the sound stream at a lower resolution, or as an MP3? If so, how would I do this without changing the video stream?) P.S.: I am limited to using Windows Media Player (11). (I previously tried MPlayer btw., but the video playback quality was surprisingly bad.)

    Read the article

  • New monitor connected to HDMI adaptor doesn't show output after booting

    - by Paul
    Hello out there in the multiple monitors’ world. I am a very old newbie in your world and need help. I just purchased a new Asus VH236H monitor and hooked it up the HDMI port of an ATI Radeon HD4300 / 4500 Series display adaptor. I left the old Princeton LCD19 (TMDS) hooked up to the DVI port of the same display adaptor. Both monitors displayed the boot sequence, after I fired good old Sarastro2 (Asus P5Q Pro Turbo – Dual Core E5300 – 2.60 GHz) up. The Asus lacked one half of a second behind the Princeton until the Windows 7 Ultimate SP 1 boot up was complete. Then the Asus displayed “HDMI NO SIGNAL” and went into hibernation. The Princeton stayed lit up as before. Both monitors are displayed on the “Screen Resolution Setup Display” and I plaid around with them for a while. The only thing I accomplished was to shove the desktop icons from the Princeton to the still hibernating Asus. The “Multiple displays:” is set to “Extend these displays”, the Orientation is “Landscape” and the Resolutions are set on both to the “recommended” one. Both monitors show that they work properly in the advanced Properties display. What am I doing wrong, what am I missing? Never mind the opinions about the different resolutions of the two monitors. I always can unhook the Princeton and give it to a Goodwill Store if I do not like the setup. I just would like to make it work. Any constructive help is very much appreciated, Thank you. Thank you Anees Bakrain Only the ATI Radeon HD 4300/4500 Series adapter is displayed in the Device Manager, for that reason I have to assume that the onboard display adaptor is not active. All 40 drivers of Sarastro2 are up to date and the HDMI cable can not be the problem because both monitors displayed the boot sequence up to the moment when Windows 7 was loaded completely. This was the moment, when the Asus monitor lost its signal. Both connectors, HDMI and DVI are connected and removing the DVI connector would not solve my problem of running both monitors simultaneously. However, your suggestions shifted my seventy one year old brain into the next gear. The only question remaining is; “Why the signals to the Asus monitor stop after the sequence is complete”. The ATI Radeon HD 4300/4500 Series adapter seems to be capable of sending simultaneous HDMI and DVI signals, what is done during the boot sequence. Why do the signals change after the boot sequence is complete is the key question or der springende Punkt? Is this a correct assumption slhck?

    Read the article

  • What is good usage scenario for Rackspace Cloud Files CDN (powered by AKAMAI) [closed]

    - by Andrew Smith
    I have just setup my website as static page via Rackspace CDN / Akamai. www.example.co.uk is an alias for d9771e6f24423091aebc-345678991111238fabcdef6114258d0e1.r61.cf3.rackcdn.com. d9771e6f24423091aebc-345678991111238fabcdef6114258d0e1.r61.cf3.rackcdn.com is an alias for a61.rackcdn.com. a61.rackcdn.com is an alias for a61.rackcdn.com.mdc.edgesuite.net. a61.rackcdn.com.mdc.edgesuite.net is an alias for a63.dscg10.akamai.net. a63.dscg10.akamai.net has address 63.166.98.41 a63.dscg10.akamai.net has address 63.166.98.40 a63.dscg10.akamai.net has IPv6 address 2001:428:4c02::cda8:ecb9 a63.dscg10.akamai.net has IPv6 address 2001:428:4c02::cda8:ed09 The HTTP header: HTTP/1.0 200 OK Last-Modified: Fri, 19 Oct 2012 23:27:41 GMT ETag: fdf9e14b77def799e09e8ce815a521da X-Timestamp: 1350689261.23382 Content-Type: text/html X-Trans-Id: tx457979be3bd746c2b4e5403a1189cdbc Cache-Control: public, max-age=900 Expires: Sat, 27 Oct 2012 22:18:56 GMT Date: Sat, 27 Oct 2012 22:03:56 GMT Content-Length: 7124 Connection: keep-alive I am wondering, if it's really the fastest solution to power the website? By investigating it thru http://www.just-ping.com/ it seems, that from many places the ping is very high, and during quick investigation I found that they use GeoIP to resolve addresses based on WHOIS, which is not accurate and because of that from many places the ping is above 300ms (for example, if ISP is in balgladore and request is routed to bangladore even if it's 300ms, for period of 1 month), while by just using Amazon Web Services and Route 53 Anycast DNS servers and only 4 EC2 instances it seems that for example India is always below 100ms, while using Akamai it goes above 300ms in some cases, and this is because Route 53 is using BGP. By quickly checking the Akamai, it seems that they are not getting feedback from the traffic - the high ping stays constant even if I keep downloading large files and videos, which is opposite to what they say on their website. They state, that they optimize the performance by taking feedback from the requests, while it seems they just use GeoIP with per City resolution (which are mostly big cities). Because of this, AWS with Route 53 / Anycast DNS seems to be much more reliable, as well EdgeCast which is using BGP, but I dont know how much does it cost to deploy static website. Actually, I dont know if EdgeCast is not a lie, because from isolated places there are many errors - so their performance is at the cost of quality of delivery, because of BGP switching the routes during transfer of large files. So I was wondering, what is really Akamai good for, because they dont seem to pose any strength in any field in what I do understand now, except they offer some software based WAF on their website, but what I really care about is the core distribiution, so the question is? Is really Akamai good for Videos? For static websites? ??? I found so far AWS most usable with most consistent ping and stable transfers.

    Read the article

  • How to get an inactive RAID device working again?

    - by Jonik
    After booting, my RAID1 device (/dev/md_d0 *) sometimes goes in some funny state and I cannot mount it. * Originally I created /dev/md0 but it has somehow changed itself into /dev/md_d0. # mount /opt mount: wrong fs type, bad option, bad superblock on /dev/md_d0, missing codepage or helper program, or other error (could this be the IDE device where you in fact use ide-scsi so that sr0 or sda or so is needed?) In some cases useful info is found in syslog - try dmesg | tail or so The RAID device appears to be inactive somehow: # cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md_d0 : inactive sda4[0](S) 241095104 blocks # mdadm --detail /dev/md_d0 mdadm: md device /dev/md_d0 does not appear to be active. Question is, how to make the device active again (using mdmadm, I presume)? (Other times it's alright (active) after boot, and I can mount it manually without problems. But it still won't mount automatically even though I have it in /etc/fstab: /dev/md_d0 /opt ext4 defaults 0 0 So a bonus question: what should I do to make the RAID device automatically mount at /opt at boot time?) This is an Ubuntu 9.10 workstation. Background info about my RAID setup in this question. Edit: My /etc/mdadm/mdadm.conf looks like this. I've never touched this file, at least by hand. # by default, scan all partitions (/proc/partitions) for MD superblocks. # alternatively, specify devices to scan, using wildcards if desired. DEVICE partitions # auto-create devices with Debian standard permissions CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST <system> # instruct the monitoring daemon where to send mail alerts MAILADDR <my mail address> # definitions of existing MD arrays # This file was auto-generated on Wed, 27 Jan 2010 17:14:36 +0200 In /proc/partitions the last entry is md_d0 at least now, after reboot, when the device happens to be active again. (I'm not sure if it would be the same when it's inactive.) Resolution: as Jimmy Hedman suggested, I took the output of mdadm --examine --scan: ARRAY /dev/md0 level=raid1 num-devices=2 UUID=de8fbd92[...] and added it in /etc/mdadm/mdadm.conf, which seems to have fixed the main problem. After changing /etc/fstab to use /dev/md0 again (instead of /dev/md_d0), the RAID device also gets automatically mounted!

    Read the article

  • New Exchange 2010 CAS cannot find domain controllers

    - by NorbyTheGeek
    I am experiencing problems migrating from Exchange 2003 to Exchange 2010. I am on the first step: installing a new 2010 Client Access Server role. The Active Directory domain functional level is 2003. All domain controllers are 2003 R2. The only existing Exchange 2003 server happens to be housed on one of the domain controllers. It is running Exchange 2003 Standard w/ SP2. IPv6 is enabled and working on all domain controllers, servers, and routers, including this new Exchange server. After installing the CAS role on a new 2008 R2 server (Hyper-V VM) I am receiving 2114 Events: Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=1600). Topology discovery failed, error 0x80040a02 (DSC_E_NO_SUITABLE_CDC). Look up the Lightweight Directory Access Protocol (LDAP) error code specified in the event description. To do this, use Microsoft Knowledge Base article 218185, "Microsoft LDAP Error Codes." Use the information in that article to learn more about the cause and resolution to this error. Use the Ping or PathPing command-line tools to test network connectivity to local domain controllers. Prior to each, I receive the following 2080 Event: Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=1600). Exchange Active Directory Provider has discovered the following servers with the following characteristics: (Server name | Roles | Enabled | Reachability | Synchronized | GC capable | PDC | SACL right | Critical Data | Netlogon | OS Version) In-site: b.company.intranet CDG 1 0 0 1 0 0 0 0 0 s.company.intranet CDG 1 0 0 1 0 0 0 0 0 Out-of-site: a.company.intranet CD- 1 0 0 0 0 0 0 0 0 o.company.intranet CD- 1 0 0 0 0 0 0 0 0 g.company.intranet CD- 1 0 0 0 0 0 0 0 0 Connectivity between the new Exchange server and all domain controllers via IPv4 and IPv6 are all working. I have verified that the new Exchange server is a member of the following groups: Exchange Servers Exchange Domain Servers Exchange Install Domain Servers Exchange Trusted Subsystem Heck, I even put the new Exchange server into Domain Admins just to see if it would help. It didn't. I can't find any evidence of Active Directory replication problems, all pre-setup Setup tasks (/PrepareLegacyExchangePermissions, /PrepareSchema, /PrepareAD, /PrepareDomain) completed successfully. The only problem so far that I haven't been able to resolve with my Active Directory is I am unable to get my IPv6 subnets into Sites and Services Where should I proceed from here?

    Read the article

  • Computer suddenly dies; screen displays weird flickering lines, then restarts

    - by Imray
    I've been having this terrible problem for a little while and just managed to get a picture of 'dead screen' for the first time and I am posting it to seek help. Randomly, at irregular intervals (typically once a week), while working on something (it's been different things every time) my computer will just suddenly go dead - the screen turns to exactly the picture below (the lines flicker a little bit), it hangs there for a few seconds and then restarts. Obviously this is extremely frustrating and I want to try to stop it. I've searched numerous postings with similar keywords but nothing exactly the same as mine. Does anyone have any idea what might be the cause of this? I would post all my system settings and installed programs but the list is long and I don't know how much relevance each item would be. If you'd like to know something specific, please comment and I'll let you know whatever you need. SPECS C:\Users\Imray>systeminfo Host Name: Imray OS Name: Microsoft Windows 7 Professional OS Version: 6.1.7600 N/A Build 7600 OS Manufacturer: Microsoft Corporation OS Configuration: Standalone Workstation OS Build Type: Multiprocessor Free Registered Owner: Imray - Owner Registered Organization: Product ID: 00371-152-9333854-85895 Original Install Date: 06/09/1999, 5:45:21 PM System Boot Time: 22/03/2013, 8:58:18 AM System Manufacturer: Gateway System Model: DX4840 System Type: x64-based PC Processor(s): 1 Processor(s) Installed. [01]: Intel64 Family 6 Model 37 Stepping 2 GenuineIntel ~3201 Mhz BIOS Version: American Megatrends Inc. P01-A3 , 17/05/2010 Windows Directory: C:\Windows System Directory: C:\Windows\system32 Boot Device: \Device\HarddiskVolume2 System Locale: en-us;English (United States) Input Locale: en-us;English (United States) Time Zone: (UTC-05:00) Eastern Time (US & Canada) Total Physical Memory: 6,135 MB Available Physical Memory: 3,632 MB Virtual Memory: Max Size: 12,268 MB Virtual Memory: Available: 8,114 MB Virtual Memory: In Use: 4,154 MB Page File Location(s): C:\pagefile.sys Domain: WORKGROUP Logon Server: \\Imray-OWNER Hotfix(s): 4 Hotfix(s) Installed. [01]: KB971033 [02]: KB958559 [03]: KB977206 [04]: KB981889 Network Card(s): 2 NIC(s) Installed. [01]: 802.11n Wireless PCI Express Card LAN Adapter Connection Name: Wireless Network Connection DHCP Enabled: Yes DHCP Server: 192.168.2.1 IP address(es) [01]: 192.168.2.13 [02]: fe80::1df1:5399:6890:91f6 [02]: Microsoft Virtual WiFi Miniport Adapter Connection Name: Wireless Network Connection 2 DHCP Enabled: Yes DHCP Server: N/A IP address(es) Graphics Card Specs Name ATI Radeon HD 5570 PNP Device ID PCI\VEN_1002&DEV_68D9&SUBSYS_E142174B&REV_00\4&18A4B35E&0&0008 Adapter Type ATI display adapter (0x68D9), ATI Technologies Inc. compatible Adapter Description ATI Radeon HD 5570 Adapter RAM 1.00 GB (1,073,741,824 bytes) Installed Drivers atiu9p64 aticfx64 aticfx64 atiu9pag aticfx32 aticfx32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64 Driver Version 8.700.0.0 INF File oem1.inf (ati2mtag_Evergreen section) Color Planes Not Available Color Table Entries 4294967296 Resolution 1920 x 1080 x 59 hertz Bits/Pixel 32 Memory Address 0xD0000000-0xDFFFFFFF Memory Address 0xFBDE0000-0xFBDFFFFF I/O Port 0x0000D000-0x0000DFFF IRQ Channel IRQ 4294967293 I/O Port 0x000003B0-0x000003BB I/O Port 0x000003C0-0x000003DF Memory Address 0xA0000-0xBFFFF Driver c:\windows\system32\drivers\atikmpag.sys (8.14.1.6095, 181.00 KB (185,344 bytes), 06/09/1999 5:59 PM)

    Read the article

  • Enterprise IPv6 Migration - End of proxypac ? Start of Point-to-Point ? +10K users

    - by Yohann
    Let's start with a diagram : We can see a "typical" IPv4 company network with : An Internet acces through a proxy An "Others companys" access through an dedicated proxy A direct access to local resources All computers have a proxy.pac file that indicates which proxy to use or whether to connect directly. Computers have access to just a local DNS (no name resolution for google.com for example.) By the way ... The company does not respect the RFC1918 internally and uses public addresses! (historical reason). The use of internet proxy explicitly makes it possible to not to have problem. What if we would migrate to IPv6? Step 1 : IPv6 internet access Internet access in IPv6 is easy. Indeed, just connect the proxy in Internet IPv4 and IPv6. There is nothing to do in internal network : Step 2 : IPv6 AND IPv4 in internal network And why not full IPv6 network directly? Because there is always the old servers that are not compatible IPv6 .. Option 1 : Same architecture as in IPv4 with a proxy pac This is probably the easiest solution. But is this the best? I think the transition to IPv6 is an opportunity not to bother with this proxy pac! Option 2 : New architecture with transparent proxy, whithout proxypac, recursive DNS Oh yes! In this new architecture, we have: Explicit Internet Proxy becomes a Transparent Internet Proxy Local DNS becomes a Normal Recursive DNS + authorative for local domains No proxypac Explicit Company Proxy becomes a Transparent Company Proxy Routing Internal Routers reditect IP of appx.ext.example.com to Company Proxy. The default gateway is the Transparent Internet proxy. Questions What do you think of this architecture IPv6? This architecture will reveal the IP addresses of our internal network but it is protected by firewalls. Is this a real big problem? Should we keep the explicit use of a proxy? -How would you make for this migration scenario? -And you, how do you do in your company? Thanks! Feel free to edit my post to make it better.

    Read the article

  • iTunes and Hulu Playback Choppy and Slow?

    - by Bart Silverstrim
    Specs: Windows XP, latest updates 1.7 ghz Pentium 4 1 gig ram DirectX 9.0c NVIDIA GeForce FX 5200 with 256 meg RAM OpenGL 2.1 The story: Okay, I had an older system laying around that I figured I would try turning into a mini-media system to connect to our TV. I put together a lot of older parts, got it into working order, etc. and hooked it up and voila'...slower, but usable system that displayed to the TV. It could run some things decently. I put in iTunes, it played video okay. Not great, but okay. Played Hulu and since we have a 1Mb download rate, the minimum for their site, there were some choppy moments when watching their shows, but I found that (sadly) changing resolution to 800x600 seemed to help with the issue when running full screen. I downloaded the application called Boxee and installed it. It wouldn't run; apparently the video card in the system supported OpenGL 1.2, and needed at least 1.4. I bought a cheap card, the 5200, with four times the memory in it and support for OpenGL 2.1. Installed, everything seemed fine. iTunes seemed to run fine, the video driver (PNY video card) came with OpenGL 2.1, and Boxee finally ran. I then upgraded to the latest drivers for the video card and ran the DirectX updater from MS. After that, the OpenGL Extension Viewer wouldn't run. It just stayed as an icon in the task bar. Also, any and all videos in iTunes stuttered and went out of sync horribly. Unwatchable. I tried watching Hulu video in Boxee, and it displayed video like it was a series of stills in a very bad powerpoint. Playing straightforward audio-only came through fine, no stutters no hiccups. I tried system restore to roll back updates to pre-directX updates (I thought that seemed to be the time that triggered the weird behavior), no joy. I tried uninstalling and reinstalling the video drivers. I installed updated audio drivers (ensoniq audiopci), nothing helped. I finally wiped the drive last night and tried reinstalling everything and restoring my iTunes content via an import from a backup. Fresh install, no updater on the video card or directx. the problem was still there although I haven't tested Hulu, the iTunes player is still stuttering like crazy if I play video, fine if I play audio. I know the processor isn't high in heft, but with one gig of RAM and the fact that it seemed to do okay before I thought that the problem must be software related. Has anyone else run into this sort of issue and have a solution other than "buy a new computer"? What specs seem to work with video at the low end for you? Right now the system is of little use other than keeping my music library and iTunes apps synced with my iPod.

    Read the article

  • General guidelines / workflow to convert or transfer video "professionally"?

    - by cloneman
    I'm an IT "professional" who sometimes has to deal with small video conversion / video cutting projects, and I'd like to learn "the right way" to do this. Every time I search Google, there's always a disaster for weird, low-maturity trialware, or random forums threads from 3-4 years ago indicating various antiquated method to do it. The big question is the following: What are the "general" guidelines and tools to transcode video into some efficient (lossless?) intermediary, for editing purposes, for the purpose of eventually re-encoding it after? It seems to me like even the simplest of formats and tasks are a disaster of endless trial & error, or expertise only known by hardened experts who have a swiss army kife of weird conversion tools that they use, almost as if mounting an attack against the project. Here are a few cases in point: Simple VOB files extracted from DVD footage can't be imported into Adobe Premiere directly. Virtualdub is an old software people keep recommending but doesn't seem to support newer formats. I don't even know how to tell with certainty which codecs a video has, and weather the image is interlaced or not, and what resolution and codecs I'm dealing with. Problems: Choosing a wrong interlace option which diminishes quality Choosing a wrong pixel aspect ratio (stretches the image) Choosing a wrong "project type" in Premiere causing footage to require scaling Being forced to use some weird program that will have any number of negative effects What I'm looking for: Books or "Real knowledge" on format conversions, recognized tools, etc. that aren't some random forum guides on how to deal with video formats. Workflow guidelines on identifying a format going from one format to another without problems as mentioned above. Documentation on what programs like Adobe Premiere can and can't do with regards to formats, so that I don't use a wrench as a hammer. TL;DR How should you convert or "prepare" a video file to ensure it will be supported by Premiere for editing? Is premiere a suitable program to handle cropping, encoding, or should other tools be used for this, when making a video montage from a variety of source formats? What are some good books to read that specifically deal with converting videos that use any number of codecs?

    Read the article

  • If Nvidia Shield can stream a game via wifi, why can I not do the same via ethernet to any other PC?

    - by Enigma
    I think it absurd that a wireless game streaming solution is the *first to hit the market when a 1000mbps+ Ethernet connection would accomplish the same feat with roughly 6x the available bandwidth. I can only assume that there must be some reason behind this or a limitation preventing this, but what? 150mbps wifi is in no way superior to a 1000mbps LAN connection aside from well wireless mobility. Not only that but I have a secondary laptop and desktop which should by hardware comparison completely outperform anything the Tegra in the Nvidia Shield can do. Is this all just a marketing scheme to force people to buy the shield for the streaming benefit? Chief among these is that NVIDIA’s Shield handheld game console will be getting a microconsole-like mode, dubbed “Shield Console Mode”, that will allow the handheld to be converted into a more traditional TV-connected console. In console mode Shield can be controlled with a Bluetooth controller, and in accordance with the higher resolution of TVs will accept 1080p game streaming from a suitably equipped PC, versus 720p in handheld mode. With that said 1080p streaming will require additional bandwidth, and while 720p can be done over WiFi NVIDIA will be requiring a hardline GigE connection for 1080p streaming (note that Shield doesn’t have Ethernet, so this is presumably being done over USB). Streaming aside, in console mode Shield will also support its traditional local gaming/application functionality. - http://www.anandtech.com/show/7435/nvidia-consolidates-game-streaming-tech-under-gamestream-brand-announces-shield-console-mode ^ This is not acceptable for me for a number of reasons not to mention the ridiculousness of having a little screen+controller unit sitting there while using a secondary controller and screen instead. That kind of redundant absurdity exemplifies how wrong of a solution that is. They need a second product for this solution without the screen or controller for it to make sense... at which point your just buying a little computer that does what most other larger computers do better. All that is required, by my understanding, is the ability to decode H.264 video compression and transmit control/feedback so by any logical comparison, one (Nvidia especially) should have no difficulty in creating an application for PC's (win32/64 environment) that does the exact same thing their android app does. I have 2 video cards capable of streaming (encoding) H.264 so by right they must be capable of decoding it I would think. I haven't found anything stating plans to allow non-shield owners to do this. Can a third party create this software or does it hinge on some limitation that only Nvidia can overcome? (*) - perhaps this isn't the first but afaik it is the first complete package.

    Read the article

  • ssh, "Last Login", `last` and OS X

    - by allentown
    I have hit the googles as much as I can on this, being specific to OS X, I am not finding an answer. Nothing is wrong, but curiosity levels are high. $ssh [email protected] Password: Last login: Wed Apr 7 21:28:03 2010 from my-laptop.local ^lonely tylenol^ Line 1 is my command line 2 is the shell asking for the password line 3 is where my question comes from line 4 comes out of /etc/motd I can find nothing in ~/ of an of the .bash* files that contains the string "Last Login", and would like to alter it. It performs some type of hostname lookup, which I can not determine. If I ssh to another host: $ssh [email protected] Last login: Wed Apr 7 21:14:51 2010 from 123-234-321-123-some.cal.isp.net.example hi there, you are on box 456 line 1 is my command line 2 is again, where my question comes from line 3 is from /etc/motd *The dash'd IP address is not reversed On this remote host, I have ~/.ssh and it's corresponding keys set up, so there was no password request Where is the "Last Login:" coming from, where does the date stamp come from, and most importantly, where does the hostname come from? While on [email protected] (box 456) $echo hostname remote.location.example456.com Or with dig, to make sure I have rDNS/PTR set up, for which I am not authoritative, but my ISP has correctly set... $dig -x 123.234.321.123 PTR remote.location.example456.com or $dig PTR 123.321.234.123.in-addr.arpa. +short remote.location.example456.com. my previous hostname used to be 123-234-321-123-some.cal.isp.net.example, which I set with hostname -s remote.location.example456.com, because it was obnoxious to see such a long name. That solves the value of $echo hostname which now returns remote.location.example456.com. Mac OS X, 10.6 is this case, does seem to honor: touch ~/.hushlogin If leave that file empty, I get nothing on the shell when I login. I want to know what controls the host resolution of the IP, and how it is all working. For example, running last reports a huge list of my logins, which have obtusely long hostnames, when they would be preferable to just be remote.location.example456.com. More confusing to me, reading the man page for wtmp and lastlog, it looks like lastlog is not used on OS X, /var/log/lastlog does not exist. Actually, none of these exist on 10.5 or 10.6: /var/run/utmp The utmp file. /var/log/wtmp The wtmp file. /var/log/lastlog The lastlog file. If I am to assume that the system is doing some kind of reverse lookup, I certainly do not know what it is, as it is not an accurate one.

    Read the article

  • game speed problem

    - by Meko
    HI..I made a little game.But this game works on every computer with different speed.I think it is about resolution.I used every thing in paintcomponent.and If I change screen size the game goes slower or faster.And if i run this game on another computer wich has different resolution it also works different. This is my game http://rapidshare.com/files/364597095/ShooterGame.2.6.0.jar and here code public class Shooter extends JFrame implements KeyListener, Runnable { JFrame frame = new JFrame(); String player; Font startFont, startSubFont, timerFont,healthFont; Image img; Image backGround; Graphics dbi; URL url1 = this.getClass().getResource("Images/p2.gif"); URL url2 = this.getClass().getResource("Images/p3.gif"); URL url3 = this.getClass().getResource("Images/p1.gif"); URL url4 = this.getClass().getResource("Images/p4.gif"); URL urlMap = this.getClass().getResource("Images/zemin.jpg"); Player p1 = new Player(5, 150, 10, 40, Color.GREEN, url3); Computer p2 = new Computer(750, 150, 10, 40, Color.BLUE, url1); Computer p3 = new Computer(0, 0, 10, 40, Color.BLUE, url2); Computer p4 = new Computer(0, 0, 10, 40, Color.BLUE, url4); ArrayList<Bullets> b = new ArrayList<Bullets>(); ArrayList<CBullets> cb = new ArrayList<CBullets>(); Thread sheap; boolean a, d, w, s; boolean toUp, toDown; boolean GameOver; boolean Level2; boolean newGame, resart, pause; int S, E; int random; int cbSpeed = 0; long timeStart, timeEnd; int timeElapsed; long GameStart, GameEnd; int GameScore; int Timer = 0; int timerStart, timerEnd; public Shooter() { sheap = new Thread(this); sheap.start(); startFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 32); startSubFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 25); timerFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 16); healthFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 16); setTitle("Shooter 2.5.1"); setBounds(350, 250, 800, 600); // setResizable(false); setBackground(Color.black); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); addKeyListener(this); a = d = w = s = false; toUp = toDown = true; GameOver = true; newGame = true; Level2 = false; S = E = 0; setVisible(true); } public void paint(Graphics g) { img = createImage(getWidth(), getHeight()); dbi = img.getGraphics(); paintComponent(dbi); g.drawImage(img, 0, 0, this); } public void paintComponent(Graphics g) { repaint(); timeStart = System.currentTimeMillis(); backGround = Toolkit.getDefaultToolkit().getImage(urlMap); g.drawImage(backGround, 0, 0, null); g.setColor(Color.red); g.setFont(healthFont); g.drawString("" + player + " Health : " + p1.health, 30, 50); g.setColor(Color.red); g.drawString("Computer Health : " + (p2.health + p3.health + p4.health), 600, 50); g.setColor(Color.BLUE); g.setFont(timerFont); g.drawString("Time : " + Timer, 330, 50); if (newGame) { g.setColor(Color.LIGHT_GRAY); g.setFont(startFont); g.drawString("Well Come To Shoot Game", 200, 190); g.drawString("Press ENTER To Start", 250, 220); g.setColor(Color.LIGHT_GRAY); g.setFont(startSubFont); g.drawString("Use W,A,S,D and Space For Fire", 200, 250); g.drawString("GOOD LUCK", 250, 280); newGame(); } if (!GameOver) { for (Bullets b1 : b) { b1.draw(g); } for (CBullets b2 : cb) { b2.draw(g); } update(); // Here MOvements for Player and For Fires } if (p1.health <= 0) { g.setColor(p2.col); g.setFont(startFont); g.drawString("Computer Wins ", 200, 190); g.drawString("Press Key R to Restart ", 200, 220); GameOver = true; } else if (p2.health <= 0 && p3.health <= 0 && p4.health <= 0) { g.setColor(p1.col); g.setFont(startFont); g.drawString(""+player+" Wins ", 200, 190); g.drawString("Press Key R to Resart ", 200, 220); GameOver = true; g.setColor(Color.MAGENTA); g.drawString(""+player+"`s Score is " + Timer, 200, 120); } if (Level2) { if (p3.health >= 0) { p3.draw(g); for (CBullets b3 : cb) { b3.draw(g); } } else { p3.x = 1000; } if (p4.health >= 0) { p4.draw(g); for (CBullets b4 : cb) { b4.draw(g); } } else { p4.x = 1000; } } if (p1.health >= 0) { p1.draw(g); } if (p2.health >= 0) { p2.draw(g); } else { p2.x = 1000; } } public void update() { if (w && p1.y > 54) { p1.moveUp(); } if (s && p1.y < 547) { p1.moveDown(); } if (a && p1.x > 0) { p1.moveLeft(); } if (d && p1.x < 200) { p1.moveRight(); } random = 1 * (int) (Math.random() * 100); if (random > 96) { if (p2.health >= 0) { CBullets bo = p2.getCBull(); bo.xVel =-1-cbSpeed; cb.add(bo); } if (Level2) { if (p3.health >= 0) { CBullets bo1 = p3.getCBull(); bo1.xVel = -2-cbSpeed; cb.add(bo1); } if (p4.health >= 0) { CBullets bo2 = p4.getCBull(); bo2.xVel = -4-cbSpeed; cb.add(bo2); } } } if (S == 1) { if (p1.health >= 0) { Bullets bu = p1.getBull(); bu.xVel = 5; b.add(bu); S += 1; } } //Here Also Problem .. When COmputer have More fire then it gaves Array Exeption . Or Player have More Fire for (int i = cb.size() -1; i = 0 ; i--) { boolean bremoved = false; for (int j = b.size() -1 ; j =0 ; j--) { if (b.get(j).rect.intersects(cb.get(i).rect) || cb.get(i).rect.intersects(b.get(j).rect)) { bremoved = true; b.remove(j); } } if(bremoved) cb.remove(i); } for (int i = 0; i < b.size(); i++) { b.get(i).move(); if (b.get(i).rect.intersects(p2.rect)) { if (p2.health >= 0) { p2.health--; b.remove(i); // System.out.println("Hited P2"); i--; continue; } } if (b.get(i).rect.intersects(p3.rect)) { if (p3.health >= 0) { p3.health--; b.remove(i); // System.out.println("Hited P3"); i--; continue; } } if (b.get(i).rect.intersects(p4.rect)) { if (p4.health >= 0) { p4.health--; b.remove(i); // System.out.println("Hited P4"); i--; continue; } } if (b.get(i).rect.x > 790) { b.remove(i); } } for (int j = 0; j < cb.size(); j++) { cb.get(j).move(); if (cb.get(j).rect.intersects(p1.rect) && cb.get(j).xVel < 0) { p1.health--; cb.remove(j); j--; continue; } } timeEnd = System.currentTimeMillis(); timeElapsed = (int) (timeEnd - timeStart); } public void level2() { if (p2.health <= 10) { Level2 = true; cbSpeed = 4; p3.x = 750; p4.x = 750; p2.speed = 10; p3.speed = 20; p4.speed = 30; } } public void keyTyped(KeyEvent e) { } public void keyPressed(KeyEvent e) { switch (e.getKeyCode()) { case KeyEvent.VK_ENTER: newGame = false; break; case KeyEvent.VK_P: pause = true; break; case KeyEvent.VK_R: resart = true; break; case KeyEvent.VK_A: a = true; break; case KeyEvent.VK_D: d = true; break; case KeyEvent.VK_W: w = true; break; case KeyEvent.VK_S: s = true; break; case KeyEvent.VK_SPACE: S += 1; break; } } public void keyReleased(KeyEvent e) { switch (e.getKeyCode()) { case KeyEvent.VK_A: a = false; break; case KeyEvent.VK_D: d = false; break; case KeyEvent.VK_W: w = false; break; case KeyEvent.VK_S: s = false; break; case KeyEvent.VK_SPACE: S = 0; break; } } public void newGame() { p1.health = 20; p2.health = 20; p3.health = 20; p4.health = 20; p3.x = 0; p4.x = 0; p2.x = 750; Level2 = false; cbSpeed = 0; p2.speed = 9; b.removeAll(b); cb.removeAll(cb); timerStart = (int) System.currentTimeMillis(); GameOver = false; } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { KeyListener k = new Shooter(); } }); } @Override public void run() { player = JOptionPane.showInputDialog(frame, "Enter Player Name", "New Player", JOptionPane.DEFAULT_OPTION); while (true) { timerEnd = (int) System.currentTimeMillis(); if (resart) { newGame(); resart = false; } if (pause) { Thread.currentThread().notify(); } try { if (!GameOver) { Timer = timerEnd - timerStart; level2(); if (p1.y < p2.y && p2.y60) { p2.moveUp(); } if (p1.y < p3.y && p3.y43) { p3.moveUp(); } if (p1.y < p4.y && p4.y43) { p4.moveUp(); } if (p1.y > p2.y && p2.y<535) { p2.moveDown(); } if (p1.y > p3.y && p3.y<535) { p3.moveDown(); } if (p1.y > p4.y && p4.y<530) { p4.moveDown(); } } if (timeElapsed < 125) { Thread.currentThread().sleep(125); } } catch (InterruptedException ex) { System.out.print("FInished"); } } } }

    Read the article

  • Using LINQ Distinct: With an Example on ASP.NET MVC SelectListItem

    - by Joe Mayo
    One of the things that might be surprising in the LINQ Distinct standard query operator is that it doesn’t automatically work properly on custom classes. There are reasons for this, which I’ll explain shortly. The example I’ll use in this post focuses on pulling a unique list of names to load into a drop-down list. I’ll explain the sample application, show you typical first shot at Distinct, explain why it won’t work as you expect, and then demonstrate a solution to make Distinct work with any custom class. The technologies I’m using are  LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP.NET MVC, ASP.NET MVC 2, and Visual Studio 2010. The function of the example program is to show a list of people that I follow.  In Twitter API vernacular, these people are called “Friends”; though I’ve never met most of them in real life. This is part of the ubiquitous language of social networking, and Twitter in particular, so you’ll see my objects named accordingly. Where Distinct comes into play is because I want to have a drop-down list with the names of the friends appearing in the list. Some friends are quite verbose, which means I can’t just extract names from each tweet and populate the drop-down; otherwise, I would end up with many duplicate names. Therefore, Distinct is the appropriate operator to eliminate the extra entries from my friends who tend to be enthusiastic tweeters. The sample doesn’t do anything with the drop-down list and I leave that up to imagination for what it’s practical purpose could be; perhaps a filter for the list if I only want to see a certain person’s tweets or maybe a quick list that I plan to combine with a TextBox and Button to reply to a friend. When the program runs, you’ll need to authenticate with Twitter, because I’m using OAuth (DotNetOpenAuth), for authentication, and then you’ll see the drop-down list of names above the grid with the most recent tweets from friends. Here’s what the application looks like when it runs: As you can see, there is a drop-down list above the grid. The drop-down list is where most of the focus of this article will be. There is some description of the code before we talk about the Distinct operator, but we’ll get there soon. This is an ASP.NET MVC2 application, written with VS 2010. Here’s the View that produces this screen: <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<TwitterFriendsViewModel>" %> <%@ Import Namespace="DistinctSelectList.Models" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">     Home Page </asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">     <fieldset>         <legend>Twitter Friends</legend>         <div>             <%= Html.DropDownListFor(                     twendVM => twendVM.FriendNames,                     Model.FriendNames,                     "<All Friends>") %>         </div>         <div>             <% Html.Telerik().Grid<TweetViewModel>(Model.Tweets)                    .Name("TwitterFriendsGrid")                    .Columns(cols =>                     {                         cols.Template(col =>                             { %>                                 <img src="<%= col.ImageUrl %>"                                      alt="<%= col.ScreenName %>" />                         <% });                         cols.Bound(col => col.ScreenName);                         cols.Bound(col => col.Tweet);                     })                    .Render(); %>         </div>     </fieldset> </asp:Content> As shown above, the Grid is from Telerik’s Extensions for ASP.NET MVC. The first column is a template that renders the user’s Avatar from a URL provided by the Twitter query. Both the Grid and DropDownListFor display properties that are collections from a TwitterFriendsViewModel class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { /// /// For finding friend info on screen /// public class TwitterFriendsViewModel { /// /// Display names of friends in drop-down list /// public List FriendNames { get; set; } /// /// Display tweets in grid /// public List Tweets { get; set; } } } I created the TwitterFreindsViewModel. The two Lists are what the View consumes to populate the DropDownListFor and Grid. Notice that FriendNames is a List of SelectListItem, which is an MVC class. Another custom class I created is the TweetViewModel (the type of the Tweets List), shown below: namespace DistinctSelectList.Models { /// /// Info on friend tweets /// public class TweetViewModel { /// /// User's avatar /// public string ImageUrl { get; set; } /// /// User's Twitter name /// public string ScreenName { get; set; } /// /// Text containing user's tweet /// public string Tweet { get; set; } } } The initial Twitter query returns much more information than we need for our purposes and this a special class for displaying info in the View.  Now you know about the View and how it’s constructed. Let’s look at the controller next. The controller for this demo performs authentication, data retrieval, data manipulation, and view selection. I’ll skip the description of the authentication because it’s a normal part of using OAuth with LINQ to Twitter. Instead, we’ll drill down and focus on the Distinct operator. However, I’ll show you the entire controller, below,  so that you can see how it all fits together: using System.Linq; using System.Web.Mvc; using DistinctSelectList.Models; using LinqToTwitter; namespace DistinctSelectList.Controllers { [HandleError] public class HomeController : Controller { private MvcOAuthAuthorization auth; private TwitterContext twitterCtx; /// /// Display a list of friends current tweets /// /// public ActionResult Index() { auth = new MvcOAuthAuthorization(InMemoryTokenManager.Instance, InMemoryTokenManager.AccessToken); string accessToken = auth.CompleteAuthorize(); if (accessToken != null) { InMemoryTokenManager.AccessToken = accessToken; } if (auth.CachedCredentialsAvailable) { auth.SignOn(); } else { return auth.BeginAuthorize(); } twitterCtx = new TwitterContext(auth); var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); var twendsVM = new TwitterFriendsViewModel { Tweets = friendTweets, FriendNames = friendNames }; return View(twendsVM); } public ActionResult About() { return View(); } } } The important part of the listing above are the LINQ to Twitter queries for friendTweets and friendNames. Both of these results are used in the subsequent population of the twendsVM instance that is passed to the view. Let’s dissect these two statements for clarification and focus on what is happening with Distinct. The query for friendTweets gets a list of the 20 most recent tweets (as specified by the Twitter API for friend queries) and performs a projection into the custom TweetViewModel class, repeated below for your convenience: var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); The LINQ to Twitter query above simplifies what we need to work with in the View and the reduces the amount of information we have to look at in subsequent queries. Given the friendTweets above, the next query performs another projection into an MVC SelectListItem, which is required for binding to the DropDownList.  This brings us to the focus of this blog post, writing a correct query that uses the Distinct operator. The query below uses LINQ to Objects, querying the friendTweets collection to get friendNames: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); The above implementation of Distinct seems normal, but it is deceptively incorrect. After running the query above, by executing the application, you’ll notice that the drop-down list contains many duplicates.  This will send you back to the code scratching your head, but there’s a reason why this happens. To understand the problem, we must examine how Distinct works in LINQ to Objects. Distinct has two overloads: one without parameters, as shown above, and another that takes a parameter of type IEqualityComparer<T>.  In the case above, no parameters, Distinct will call EqualityComparer<T>.Default behind the scenes to make comparisons as it iterates through the list. You don’t have problems with the built-in types, such as string, int, DateTime, etc, because they all implement IEquatable<T>. However, many .NET Framework classes, such as SelectListItem, don’t implement IEquatable<T>. So, what happens is that EqualityComparer<T>.Default results in a call to Object.Equals, which performs reference equality on reference type objects.  You don’t have this problem with value types because the default implementation of Object.Equals is bitwise equality. However, most of your projections that use Distinct are on classes, just like the SelectListItem used in this demo application. So, the reason why Distinct didn’t produce the results we wanted was because we used a type that doesn’t define its own equality and Distinct used the default reference equality. This resulted in all objects being included in the results because they are all separate instances in memory with unique references. As you might have guessed, the solution to the problem is to use the second overload of Distinct that accepts an IEqualityComparer<T> instance. If you were projecting into your own custom type, you could make that type implement IEqualityComparer<T>, but SelectListItem belongs to the .NET Framework Class Library.  Therefore, the solution is to create a custom type to implement IEqualityComparer<T>, as in the SelectListItemComparer class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { public class SelectListItemComparer : EqualityComparer { public override bool Equals(SelectListItem x, SelectListItem y) { return x.Value.Equals(y.Value); } public override int GetHashCode(SelectListItem obj) { return obj.Value.GetHashCode(); } } } The SelectListItemComparer class above doesn’t implement IEqualityComparer<SelectListItem>, but rather derives from EqualityComparer<SelectListItem>. Microsoft recommends this approach for consistency with the behavior of generic collection classes. However, if your custom type already derives from a base class, go ahead and implement IEqualityComparer<T>, which will still work. EqualityComparer is an abstract class, that implements IEqualityComparer<T> with Equals and GetHashCode abstract methods. For the purposes of this application, the SelectListItem.Value property is sufficient to determine if two items are equal.   Since SelectListItem.Value is type string, the code delegates equality to the string class. The code also delegates the GetHashCode operation to the string class.You might have other criteria in your own object and would need to define what it means for your object to be equal. Now that we have an IEqualityComparer<SelectListItem>, let’s fix the problem. The code below modifies the query where we want distinct values: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct(new SelectListItemComparer()) .ToList(); Notice how the code above passes a new instance of SelectListItemComparer as the parameter to the Distinct operator. Now, when you run the application, the drop-down list will behave as you expect, showing only a unique set of names. In addition to Distinct, other LINQ Standard Query Operators have overloads that accept IEqualityComparer<T>’s, You can use the same techniques as shown here, with SelectListItemComparer, with those other operators as well. Now you know how to resolve problems with getting Distinct to work properly and also have a way to fix problems with other operators that require equality comparisons. @JoeMayo

    Read the article

  • SQL SERVER – Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

    - by pinaldave
    In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Signal Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Signal Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Signal Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the Signalwait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the Signal wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the Signal wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

    Read the article

  • Parallelism in .NET – Part 3, Imperative Data Parallelism: Early Termination

    - by Reed
    Although simple data parallelism allows us to easily parallelize many of our iteration statements, there are cases that it does not handle well.  In my previous discussion, I focused on data parallelism with no shared state, and where every element is being processed exactly the same. Unfortunately, there are many common cases where this does not happen.  If we are dealing with a loop that requires early termination, extra care is required when parallelizing. Often, while processing in a loop, once a certain condition is met, it is no longer necessary to continue processing.  This may be a matter of finding a specific element within the collection, or reaching some error case.  The important distinction here is that, it is often impossible to know until runtime, what set of elements needs to be processed. In my initial discussion of data parallelism, I mentioned that this technique is a candidate when you can decompose the problem based on the data involved, and you wish to apply a single operation concurrently on all of the elements of a collection.  This covers many of the potential cases, but sometimes, after processing some of the elements, we need to stop processing. As an example, lets go back to our previous Parallel.ForEach example with contacting a customer.  However, this time, we’ll change the requirements slightly.  In this case, we’ll add an extra condition – if the store is unable to email the customer, we will exit gracefully.  The thinking here, of course, is that if the store is currently unable to email, the next time this operation runs, it will handle the same situation, so we can just skip our processing entirely.  The original, serial case, with this extra condition, might look something like the following: foreach(var customer in customers) { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { // Exit gracefully if we fail to email, since this // entire process can be repeated later without issue. if (theStore.EmailCustomer(customer) == false) break; customer.LastEmailContact = DateTime.Now; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re processing our loop, but at any point, if we fail to send our email successfully, we just abandon this process, and assume that it will get handled correctly the next time our routine is run.  If we try to parallelize this using Parallel.ForEach, as we did previously, we’ll run into an error almost immediately: the break statement we’re using is only valid when enclosed within an iteration statement, such as foreach.  When we switch to Parallel.ForEach, we’re no longer within an iteration statement – we’re a delegate running in a method. This needs to be handled slightly differently when parallelized.  Instead of using the break statement, we need to utilize a new class in the Task Parallel Library: ParallelLoopState.  The ParallelLoopState class is intended to allow concurrently running loop bodies a way to interact with each other, and provides us with a way to break out of a loop.  In order to use this, we will use a different overload of Parallel.ForEach which takes an IEnumerable<T> and an Action<T, ParallelLoopState> instead of an Action<T>.  Using this, we can parallelize the above operation by doing: Parallel.ForEach(customers, (customer, parallelLoopState) => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { // Exit gracefully if we fail to email, since this // entire process can be repeated later without issue. if (theStore.EmailCustomer(customer) == false) parallelLoopState.Break(); else customer.LastEmailContact = DateTime.Now; } }); There are a couple of important points here.  First, we didn’t actually instantiate the ParallelLoopState instance.  It was provided directly to us via the Parallel class.  All we needed to do was change our lambda expression to reflect that we want to use the loop state, and the Parallel class creates an instance for our use.  We also needed to change our logic slightly when we call Break().  Since Break() doesn’t stop the program flow within our block, we needed to add an else case to only set the property in customer when we succeeded.  This same technique can be used to break out of a Parallel.For loop. That being said, there is a huge difference between using ParallelLoopState to cause early termination and to use break in a standard iteration statement.  When dealing with a loop serially, break will immediately terminate the processing within the closest enclosing loop statement.  Calling ParallelLoopState.Break(), however, has a very different behavior. The issue is that, now, we’re no longer processing one element at a time.  If we break in one of our threads, there are other threads that will likely still be executing.  This leads to an important observation about termination of parallel code: Early termination in parallel routines is not immediate.  Code will continue to run after you request a termination. This may seem problematic at first, but it is something you just need to keep in mind while designing your routine.  ParallelLoopState.Break() should be thought of as a request.  We are telling the runtime that no elements that were in the collection past the element we’re currently processing need to be processed, and leaving it up to the runtime to decide how to handle this as gracefully as possible.  Although this may seem problematic at first, it is a good thing.  If the runtime tried to immediately stop processing, many of our elements would be partially processed.  It would be like putting a return statement in a random location throughout our loop body – which could have horrific consequences to our code’s maintainability. In order to understand and effectively write parallel routines, we, as developers, need a subtle, but profound shift in our thinking.  We can no longer think in terms of sequential processes, but rather need to think in terms of requests to the system that may be handled differently than we’d first expect.  This is more natural to developers who have dealt with asynchronous models previously, but is an important distinction when moving to concurrent programming models. As an example, I’ll discuss the Break() method.  ParallelLoopState.Break() functions in a way that may be unexpected at first.  When you call Break() from a loop body, the runtime will continue to process all elements of the collection that were found prior to the element that was being processed when the Break() method was called.  This is done to keep the behavior of the Break() method as close to the behavior of the break statement as possible. We can see the behavior in this simple code: var collection = Enumerable.Range(0, 20); var pResult = Parallel.ForEach(collection, (element, state) => { if (element > 10) { Console.WriteLine("Breaking on {0}", element); state.Break(); } Console.WriteLine(element); }); If we run this, we get a result that may seem unexpected at first: 0 2 1 5 6 3 4 10 Breaking on 11 11 Breaking on 12 12 9 Breaking on 13 13 7 8 Breaking on 15 15 What is occurring here is that we loop until we find the first element where the element is greater than 10.  In this case, this was found, the first time, when one of our threads reached element 11.  It requested that the loop stop by calling Break() at this point.  However, the loop continued processing until all of the elements less than 11 were completed, then terminated.  This means that it will guarantee that elements 9, 7, and 8 are completed before it stops processing.  You can see our other threads that were running each tried to break as well, but since Break() was called on the element with a value of 11, it decides which elements (0-10) must be processed. If this behavior is not desirable, there is another option.  Instead of calling ParallelLoopState.Break(), you can call ParallelLoopState.Stop().  The Stop() method requests that the runtime terminate as soon as possible , without guaranteeing that any other elements are processed.  Stop() will not stop the processing within an element, so elements already being processed will continue to be processed.  It will prevent new elements, even ones found earlier in the collection, from being processed.  Also, when Stop() is called, the ParallelLoopState’s IsStopped property will return true.  This lets longer running processes poll for this value, and return after performing any necessary cleanup. The basic rule of thumb for choosing between Break() and Stop() is the following. Use ParallelLoopState.Stop() when possible, since it terminates more quickly.  This is particularly useful in situations where you are searching for an element or a condition in the collection.  Once you’ve found it, you do not need to do any other processing, so Stop() is more appropriate. Use ParallelLoopState.Break() if you need to more closely match the behavior of the C# break statement. Both methods behave differently than our C# break statement.  Unfortunately, when parallelizing a routine, more thought and care needs to be put into every aspect of your routine than you may otherwise expect.  This is due to my second observation: Parallelizing a routine will almost always change its behavior. This sounds crazy at first, but it’s a concept that’s so simple its easy to forget.  We’re purposely telling the system to process more than one thing at the same time, which means that the sequence in which things get processed is no longer deterministic.  It is easy to change the behavior of your routine in very subtle ways by introducing parallelism.  Often, the changes are not avoidable, even if they don’t have any adverse side effects.  This leads to my final observation for this post: Parallelization is something that should be handled with care and forethought, added by design, and not just introduced casually.

    Read the article

  • SQL SERVER – Single Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

    - by pinaldave
    In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Single Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Single Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Single Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the single wait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the single wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the single wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

    Read the article

  • Parallelism in .NET – Part 9, Configuration in PLINQ and TPL

    - by Reed
    Parallel LINQ and the Task Parallel Library contain many options for configuration.  Although the default configuration options are often ideal, there are times when customizing the behavior is desirable.  Both frameworks provide full configuration support. When working with Data Parallelism, there is one primary configuration option we often need to control – the number of threads we want the system to use when parallelizing our routine.  By default, PLINQ and the TPL both use the ThreadPool to schedule tasks.  Given the major improvements in the ThreadPool in CLR 4, this default behavior is often ideal.  However, there are times that the default behavior is not appropriate.  For example, if you are working on multiple threads simultaneously, and want to schedule parallel operations from within both threads, you might want to consider restricting each parallel operation to using a subset of the processing cores of the system.  Not doing this might over-parallelize your routine, which leads to inefficiencies from having too many context switches. In the Task Parallel Library, configuration is handled via the ParallelOptions class.  All of the methods of the Parallel class have an overload which accepts a ParallelOptions argument. We configure the Parallel class by setting the ParallelOptions.MaxDegreeOfParallelism property.  For example, let’s revisit one of the simple data parallel examples from Part 2: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re looping through an image, and calling a method on each pixel in the image.  If this was being done on a separate thread, and we knew another thread within our system was going to be doing a similar operation, we likely would want to restrict this to using half of the cores on the system.  This could be accomplished easily by doing: var options = new ParallelOptions(); options.MaxDegreeOfParallelism = Math.Max(Environment.ProcessorCount / 2, 1); Parallel.For(0, pixelData.GetUpperBound(0), options, row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Now, we’re restricting this routine to using no more than half the cores in our system.  Note that I included a check to prevent a single core system from supplying zero; without this check, we’d potentially cause an exception.  I also did not hard code a specific value for the MaxDegreeOfParallelism property.  One of our goals when parallelizing a routine is allowing it to scale on better hardware.  Specifying a hard-coded value would contradict that goal. Parallel LINQ also supports configuration, and in fact, has quite a few more options for configuring the system.  The main configuration option we most often need is the same as our TPL option: we need to supply the maximum number of processing threads.  In PLINQ, this is done via a new extension method on ParallelQuery<T>: ParallelEnumerable.WithDegreeOfParallelism. Let’s revisit our declarative data parallelism sample from Part 6: double min = collection.AsParallel().Min(item => item.PerformComputation()); Here, we’re performing a computation on each element in the collection, and saving the minimum value of this operation.  If we wanted to restrict this to a limited number of threads, we would add our new extension method: int maxThreads = Math.Max(Environment.ProcessorCount / 2, 1); double min = collection .AsParallel() .WithDegreeOfParallelism(maxThreads) .Min(item => item.PerformComputation()); This automatically restricts the PLINQ query to half of the threads on the system. PLINQ provides some additional configuration options.  By default, PLINQ will occasionally revert to processing a query in parallel.  This occurs because many queries, if parallelized, typically actually cause an overall slowdown compared to a serial processing equivalent.  By analyzing the “shape” of the query, PLINQ often decides to run a query serially instead of in parallel.  This can occur for (taken from MSDN): Queries that contain a Select, indexed Where, indexed SelectMany, or ElementAt clause after an ordering or filtering operator that has removed or rearranged original indices. Queries that contain a Take, TakeWhile, Skip, SkipWhile operator and where indices in the source sequence are not in the original order. Queries that contain Zip or SequenceEquals, unless one of the data sources has an originally ordered index and the other data source is indexable (i.e. an array or IList(T)). Queries that contain Concat, unless it is applied to indexable data sources. Queries that contain Reverse, unless applied to an indexable data source. If the specific query follows these rules, PLINQ will run the query on a single thread.  However, none of these rules look at the specific work being done in the delegates, only at the “shape” of the query.  There are cases where running in parallel may still be beneficial, even if the shape is one where it typically parallelizes poorly.  In these cases, you can override the default behavior by using the WithExecutionMode extension method.  This would be done like so: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .Select(i => i.PerformComputation()) .Reverse(); Here, the default behavior would be to not parallelize the query unless collection implemented IList<T>.  We can force this to run in parallel by adding the WithExecutionMode extension method in the method chain. Finally, PLINQ has the ability to configure how results are returned.  When a query is filtering or selecting an input collection, the results will need to be streamed back into a single IEnumerable<T> result.  For example, the method above returns a new, reversed collection.  In this case, the processing of the collection will be done in parallel, but the results need to be streamed back to the caller serially, so they can be enumerated on a single thread. This streaming introduces overhead.  IEnumerable<T> isn’t designed with thread safety in mind, so the system needs to handle merging the parallel processes back into a single stream, which introduces synchronization issues.  There are two extremes of how this could be accomplished, but both extremes have disadvantages. The system could watch each thread, and whenever a thread produces a result, take that result and send it back to the caller.  This would mean that the calling thread would have access to the data as soon as data is available, which is the benefit of this approach.  However, it also means that every item is introducing synchronization overhead, since each item needs to be merged individually. On the other extreme, the system could wait until all of the results from all of the threads were ready, then push all of the results back to the calling thread in one shot.  The advantage here is that the least amount of synchronization is added to the system, which means the query will, on a whole, run the fastest.  However, the calling thread will have to wait for all elements to be processed, so this could introduce a long delay between when a parallel query begins and when results are returned. The default behavior in PLINQ is actually between these two extremes.  By default, PLINQ maintains an internal buffer, and chooses an optimal buffer size to maintain.  Query results are accumulated into the buffer, then returned in the IEnumerable<T> result in chunks.  This provides reasonably fast access to the results, as well as good overall throughput, in most scenarios. However, if we know the nature of our algorithm, we may decide we would prefer one of the other extremes.  This can be done by using the WithMergeOptions extension method.  For example, if we know that our PerformComputation() routine is very slow, but also variable in runtime, we may want to retrieve results as they are available, with no bufferring.  This can be done by changing our above routine to: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.NotBuffered) .Select(i => i.PerformComputation()) .Reverse(); On the other hand, if are already on a background thread, and we want to allow the system to maximize its speed, we might want to allow the system to fully buffer the results: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.FullyBuffered) .Select(i => i.PerformComputation()) .Reverse(); Notice, also, that you can specify multiple configuration options in a parallel query.  By chaining these extension methods together, we generate a query that will always run in parallel, and will always complete before making the results available in our IEnumerable<T>.

    Read the article

< Previous Page | 131 132 133 134 135 136 137 138 139 140 141 142  | Next Page >