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• Secure password transmission over unencrypted tcp/ip

  - by academicRobot

  I'm in the designing stages of a custom tcp/ip protocol for mobile client-server communication. When not required (data is not sensitive), I'd like to avoid using SSL for overhead reasons (both in handshake latency and conserving cycles). My question is, what is the best practices way of transmitting authentication information over an unencrypted connection? Currently, I'm liking SRP or J-PAKE (they generate secure session tokens, are hash/salt friendly, and allow kicking into TLS when necessary), which I believe are both implemented in OpenSSL. However, I am a bit wary since I don't see many people using these algorithms for this purpose. Would also appreciate pointers to any materials discussing this topic in general, since I had trouble finding any.

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• ASP NET forms Authorization: how to reduce duration?

  - by eddo

  I've got a web page which is implementing cookie based ASPNET Forms Authentication. Once the user has logged in the page, he can edit some information using a form which is created using a partialview and returned to him as a dialog for editing. The action linked to the partial view is decorated as follows: [HttpGet] [OutputCache(Duration = 0, VaryByParam = "None")] [Authorize(Roles = "test")] public ActionResult changeTripInfo(int tripID, bool ovride=false) { ... } The problem i am experiencing is the latency between the request and the time when the dialog is shown to the user: time ranges between 800 and 1100 ms which is not justified by the complexity of the form. Investigating with Glimpse turns out that the time to process the AuthorizeAttribute (see snip) sums up to at least 650 ms which is troubling me. Looking at the Sql server log, the call which checks the user roles takes, as expected, virtually nothing (duration 0). How can I reduce this time? Am I missing some optimization?

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• Faking a Single Address Space

  - by dsimcha

  I have a large scientific computing task that parallelizes very well with SMP, but at too fine grained a level to be easily parallelized via explicit message passing. I'd like to parallelize it across address spaces and physical machines. Is it feasible to create a scheduler that would parallelize already multithreaded code across multiple physical computers under the following conditions: The code is already multithreaded and can scale pretty well on SMP configurations. The fact that not all of the threads are running in the same address space or on the same physical machine must be transparent to the program, even if this comes at a significant performance penalty in some use cases. You may assume that all of the physical machines involved are running operating systems and CPU architectures that are binary compatible. Things like locks and atomic operations may be slow (having network latency to deal with and all) but must "just work".

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• How do I create a list of timedeltas in python?

  - by eunhealee

  I've been searching through this website and have seen multiple references to time deltas, but haven't quite found what I'm looking for. Basically, I have a list of messages that are received by a comms server and I want to calcuate the latency time between each message out and in. It looks like this: 161336.934072 - TMsg out: [O] enter order. RefID [123] OrdID [4568] 161336.934159 - TMsg in: [A] accepted. ordID [456] RefNumber [123] Mixed in with these messages are other messages as well, however, I only want to capture the difference between the Out messages and in messages with the same RefID. So far, to sort out from the main log which messages are Tmessages I've been doing this, but it's really inefficient. I don't need to be making new files everytime.: big_file = open('C:/Users/kdalton/Documents/Minicomm.txt', 'r') small_file1 = open('small_file1.txt', 'w') for line in big_file: if 'T' in line: small_file1.write(line) big_file.close() small_file1.close() How do I calculate the time deltas between the two messages and sort out these messages from the main log?

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• Parallelism on two duo-core processor system

  - by Qin

  I wrote a Java program that draw the Mandelbrot image. To make it interesting, I divided the for loop that calculates the color of each pixel into 2 halves; each half will be executed as a thread thus parallelizing the task. On a two core one cpu system, the performance of using two thread approach vs just one main thread is nearly two fold. My question is on a two dual-core processor system, will the parallelized task be split among different processor instead of just utilize the two core on one processor? I suppose the former scenario will be slower than the latter one simply because the latency of communicating between 2 CPU over the motherboard wires. Any ideas? Thanks

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• What is the absolute fastest way to implement a concurrent queue with ONLY one consumer and one producer?

  - by JohnPristine

  java.util.concurrent.ConcurrentLinkedQueue comes to mind, but is it really optimum for this two-thread scenario? I am looking for the minimum latency possible on both sides (producer and consumer). If the queue is empty you can immediately return null AND if the queue is full you can immediately discard the entry you are offering. Does ConcurrentLinkedQueue use super fast and light locks (AtomicBoolean) ? Has anyone benchmarked ConcurrentLinkedQueue or knows about the ultimate fastest way of doing that? Additional Details: I imagine the queue should be a fair one, meaning the consumer should not make the consumer wait any longer than it needs (by front-running it) and vice-versa.

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• Database/NoSQL - Lowest latecy way to retreive the following data...

  - by Nickb

  I have a real estate application and a "house" contains the following information: house: - house_id - address - city - state - zip - price - sqft - bedrooms - bathrooms - geo_latitude - geo_longitude I need to perform an EXTREMELY fast (low latency) retrieval of all homes within a geo-coordinate box. Something like the SQL below (if I were to use a database): SELECT * from houses WHERE latitude IS BETWEEN xxx AND yyy AND longitude IS BETWEEN www AND zzz Question: What would be the quickest way for me to store this information so that I can perform the fastest retrieval of data based on latitude & longitude? (e.g. database, NoSQL, memcache, etc)?

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• Delete/move a UITableView row that's attached to a web service.

  - by Kevin L.

  Deleting or moving rows for a UITableView that is backed with local data (e.g., NSArray) is easy and instantaneous: Remove the value from the array. Call deleteRowsAtIndexPaths:withRowAnimation:. Profit! But my table view communicates with a web service, which means once the "Delete" button on that row gets tapped, I have to forward a request on to the server (via ASIHTTPRequest, of course), get the response, and then tell the table view to run its little delete-row animation, all with a few seconds of latency in between. From a high-level, what's the best way to do that? Throw some callback selector into ASIHTTPRequest's userInfo dictionary? KVO? Bonus points for some nice UI touch, like some kind of spinner on the soon-to-be-deleted cell.

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• Google App Engine, Java, and HTTP Performance

  - by polyclef

  A friend and I are currently working on a turn-based game with chat with both desktop browser and Android clients, with Google App Engine as the server. We're using the Java API for GAE and using HTTP for communication with the server. We've implemented simple chat functionality, and we're getting undesirable latencies 1-3 seconds from both the browser and Android clients while just posting simple one-word chat messages. My friend thought it would be best to use XMPP instead of HTTP, but we want to use a Google Accounts cookie for authentication from the Android client, and according to the GAE documentation, XMPP clients cannot use a Google Accounts cookie and must use the user's password. Does anyone have any suggestions as to where the latency might be coming from, how to troubleshoot it, and/or what to do about it? Also, is anyone aware of any opensource implementations of chat (or something similar) on GAE done in Java? Can't seem to find any.

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• x86 linux - how to create custom malloc with address hint

  - by nandu

  Hi, I want to create a custom malloc which allocates memory blocks within a given address range. I am writing a pthreads application in which threads are bound to unique cores on a many-core machine. The memory controllers are statically mapped, so that certain range of addresses on main memory are electrically closer to a core. I want to minimize the latency of communication between cores and main memory by allocating thread memory on these "closer" regions. Any ideas would be most appreciated. Thank you! Nandu

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• How to get at TCP RTT on Windows (Linux TCP_INFO) as an user

  - by FredAlkin

  I am porting a streaming TCP app from Linux to Windows. The app streams real-time audio data using a preexisting TCP protocol (so switching to UDP isn't an option). Further, I wish to avoid being "part of the problem" and requiring Administrator rights. The Linux code uses getsockopt(... ,SOL_TCP, TCP_INFO, ..) to get the RTT (round trip time) information from the TCP connection. The application level uses this to throttle the amount of data sent over the connection (apparently to balance quality with latency). Is there an equivalent to TCP_INFO on WIndows? (google tells me that Win2K and later supports "TCP Timestamps" which would provide this information, but I've yet to find a way to get at it. Thanks in advance.

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• Game network physics collision

  - by Jonas Byström

  How to simulating two client-controlled vehicles colliding (sensibly) in a typical client/server setup for a network game? I did read this eminent blog post on how to do distributed network physics in general (without traditional client prediction), but this question is specifically on how to handle collisions of owned objects. Example Say client A is 20 ms ahead of server, client B 300 ms ahead of server (counting both latency and maximum jitter). This means that when the two vehicles collide, both clients will see the other as 320 ms behind - in the opposite direction of the velocity of the other vehicle. Head-to-head on a Swedish highway means a difference of 16 meters/17.5 yards! What not to try It is virtually impossible to extrapolate the positions, since I also have very complex vehicles with joints and bodies all over, which in turn have linear and angular positions, velocities and accelerations, not to mention states from user input.

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• To use an api or store a large dataset in a rails app?

  - by Dave

  Hi all- I am working on a site that has the potential to need a LOT of space. Basically we hope to have every video game every created stored in a database along with an image of the cover. There are some api's out there that might be able to help, like GiantBomb's (www.giantbomb.com). We are trying to decide whether to store the data locally and if so where to find that comprehensive a list, or make calls to the api on demand. The problem with the latter is likely latency and also downtime problems. Assuming we want to store it locally here are the questions: 1) Where can we find this kind of data (yes, I looked on google, and no I couldnt find anything:)) 2) What is the most efficient way to encode and store the images? Thanks!

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• I am requesting ideas on manipulating output from an array and parse to something useful

  - by Cyber Demon

  First I am new to PS scripting. Please be gentle. This simple script I have written is ok. $Iplist = Get-Content ips.txt foreach ($ip in $Iplist) { .\psping -h -n 3 -w 0 $ip >> results.csv } Move-Item "C:\ping\results.csv" ("C:\ping\aftermath\{0:yyyyMMddhhmm}.csv" -f (get-date)) The Output is as follows, as an example (I used www.google.com): Pinging 74.125.225.48 with 32 bytes of data: 3 iterations (warmup 0) ping test: Reply from 74.125.225.48: 54.14ms Reply from 74.125.225.48: 54.85ms Reply from 74.125.225.48: 54.48ms Ping statistics for 74.125.225.48: Sent = 3, Received = 3, Lost = 0 (0% loss), Minimum = 54.14ms, Maximum = 54.85ms, Average = 54.49ms Latency Count 54.14 1 54.17 0 54.21 0 54.25 0 54.29 0 54.32 0 54.36 0 54.4 0 54.44 0 54.47 1 54.51 0 54.55 0 54.59 0 54.62 0 54.66 0 54.7 0 54.74 0 54.77 0 54.81 0 54.85 1 What I'm looking for is something to show me the following as an output. ServerIP Name TimeStamp Results AverageResponseTime in milli-seconds www.google.com 2014-08-14T16:09:59 Up 53 Can you guide me?

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• Using linked servers, OPENROWSET and OPENQUERY

  - by BuckWoody

  SQL Server has a few mechanisms to reach out to another server (even another server type) and query data from within a Transact-SQL statement. Among them are a set of stored credentials and information (called a Linked Server), a statement that uses a linked server called called OPENQUERY, another called OPENROWSET, and one called OPENDATASOURCE. This post isn’t about those particular functions or statements – hit the links for more if you’re new to those topics. I’m actually more concerned about where I see these used than the particular method. In many cases, a Linked server isn’t another Relational Database Management System (RDMBS) like Oracle or DB2 (which is possible with a linked server), but another SQL Server. My concern is that linked servers are the new Data Transformation Services (DTS) from SQL Server 2000 – something that was designed for one purpose but which is being morphed into something much more. In the case of DTS, most of us turned that feature into a full-fledged job system. What was designed as a simple data import and export system has been pressed into service doing logic, routing and timing. And of course we all know how painful it was to move off of a complex DTS system onto SQL Server Integration Services. In the case of linked servers, what should be used as a method of running a simple query or two on another server where you have occasional connection or need a quick import of a small data set is morphing into a full federation strategy. In some cases I’ve seen a complex web of linked servers, and when credentials, names or anything else changes there are huge problems. Now don’t get me wrong – linked servers and other forms of distributing queries is a fantastic set of tools that we have to move data around. I’m just saying that when you start having lots of workarounds and when things get really complicated, you might want to step back a little and ask if there’s a better way. Are you able to tolerate some latency? Perhaps you’re able to use Service Broker. Would you like to be platform-independent on the data source? Perhaps a middle-tier might make more sense, abstracting the queries there and sending them to the proper server. Designed properly, I’ve seen these systems scale further and be more resilient than loading up on linked servers. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Internet Protocol Suite: Transition Control Protocol (TCP) vs. User Datagram Protocol (UDP)

  How do we communicate over the Internet?  How is data transferred from one machine to another? These types of act ivies can only be done by using one of two Internet protocols currently. The collection of Internet Protocol consists of the Transition Control Protocol (TCP) and the User Datagram Protocol (UDP).  Both protocols are used to send data between two network end points, however they both have very distinct ways of transporting data from one endpoint to another. If transmission speed and reliability is the primary concern when trying to transfer data between two network endpoints then TCP is the proper choice. When a device attempts to send data to another endpoint using TCP it creates a direct connection between both devices until the transmission has completed. The direct connection between both devices ensures the reliability of the transmission due to the fact that no intermediate devices are needed to transfer the data. Due to the fact that both devices have to continuously poll the connection until transmission has completed increases the resources needed to perform the transmission. An example of this type of direct communication can be seen when a teacher tells a students to do their homework. The teacher is talking directly to the students in order to communicate that the homework needs to be done.  Students can then ask questions about the assignment to ensure that they have received the proper instructions for the assignment. UDP is a less resource intensive approach to sending data between to network endpoints. When a device uses UDP to send data across a network, the data is broken up and repackaged with the destination address. The sending device then releases the data packages to the network, but cannot ensure when or if the receiving device will actually get the data.  The sending device depends on other devices on the network to forward the data packages to the destination devices in order to complete the transmission. As you can tell this type of transmission is less resource intensive because not connection polling is needed,  but should not be used for transmitting data with speed or reliability requirements. This is due to the fact that the sending device can not ensure that the transmission is received.  An example of this type of communication can be seen when a teacher tells a student that they would like to speak with their parents. The teacher is relying on the student to complete the transmission to the parents, and the teacher has no guarantee that the student will actually inform the parents about the request. Both TCP and UPD are invaluable when attempting to send data across a network, but depending on the situation one protocol may be better than the other. Before deciding on which protocol to use an evaluation for transmission speed, reliability, latency, and overhead must be completed in order to define the best protocol for the situation.  

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• Raymond James at Oracle OpenWorld: Showcasing Real Time Data Integration.

  - by Christophe Dupupet

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} In today’s always-on, always connected world, integrating data in real-time is a necessity for most companies and most industries. The experts at Raymond James Financials, using Oracle GoldenGate and Oracle Data Integrator, have designed a real-time data integration solution for their operational data store and services that support applications throughout the enterprise . They boast an amazing number of daily executions, while dramatically reducing data latency,  increasing data service performance, and speeding time to market. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} To know more on how they have achieved such results, come listen to Ryan Fonnett and Tim Garrod: they will explain how they implemented their solution, and also illustrate their explanations with a live demonstration of their work. A presentation not to be missed! Real-Time Data Integrationwith Oracle Data Integratorat Raymond James October 1st 2012 at 4:45pm Moscone West, room 3005

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• Dell XPS 15 (L502x) sound problem

  - by lauramolenaar

  I have a problem with my sound on my Dell XPS 15. First, when I had Windows 7, my sound was pretty good (I have a JBL 2.1 speaker system with Waves Maxx audio), but since I installed Ubuntu 12.04 it sounded very cheap and as if I put my laptop in a tin can. I've already tried installing alsa-hda-dkms from the alsa-daily ppa (http://ppa.launchpad.net/ubuntu-audio-dev/alsa-daily) This is my audio controller: laura@laura-XPS-L502X:~$ lspci -v | grep -A7 -i audio 00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05) Subsystem: Dell Device 04b6 Flags: bus master, fast devsel, latency 0, IRQ 51 Memory at f1c00000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel I hope you can help me, and you can always ask me for more information. Result of aplay -l: **** List of PLAYBACK Hardware Devices **** card 0: PCH [HDA Intel PCH], device 0: ALC665 Analog [ALC665 Analog] Subdevices: 0/1 Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 1: ALC665 Digital [ALC665 Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0] Subdevices: 1/1 Subdevice #0: subdevice #0 Result of aplay -L: default Playback/recording through the PulseAudio sound server sysdefault:CARD=PCH HDA Intel PCH, ALC665 Analog Default Audio Device front:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog Front speakers surround40:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog 4.0 Surround output to Front and Rear speakers surround41:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Digital IEC958 (S/PDIF) Digital Audio Output hdmi:CARD=PCH,DEV=0 HDA Intel PCH, HDMI 0 HDMI Audio Output dmix:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog Direct sample mixing device dmix:CARD=PCH,DEV=1 HDA Intel PCH, ALC665 Digital Direct sample mixing device dmix:CARD=PCH,DEV=3 HDA Intel PCH, HDMI 0 Direct sample mixing device dsnoop:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog Direct sample snooping device dsnoop:CARD=PCH,DEV=1 HDA Intel PCH, ALC665 Digital Direct sample snooping device dsnoop:CARD=PCH,DEV=3 HDA Intel PCH, HDMI 0 Direct sample snooping device hw:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog Direct hardware device without any conversions hw:CARD=PCH,DEV=1 HDA Intel PCH, ALC665 Digital Direct hardware device without any conversions hw:CARD=PCH,DEV=3 HDA Intel PCH, HDMI 0 Direct hardware device without any conversions plughw:CARD=PCH,DEV=0 HDA Intel PCH, ALC665 Analog Hardware device with all software conversions plughw:CARD=PCH,DEV=1 HDA Intel PCH, ALC665 Digital Hardware device with all software conversions plughw:CARD=PCH,DEV=3 HDA Intel PCH, HDMI 0 Hardware device with all software conversions

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• NEC Corporation uPD720200 USB 3.0 controller doesn't run at full speed

  - by Radek Zyskowski

  I have fresh install of Ubuntu 10.10. I have external HD on USB 3.0. Trying to connect this via PCI Express NEC controller. dmesg: [ 8966.820078] usb 6-3: new high speed USB device using xhci_hcd and address 0 [ 8966.839831] xhci_hcd 0000:02:00.0: WARN: short transfer on control ep [ 8966.840580] xhci_hcd 0000:02:00.0: WARN: short transfer on control ep [ 8966.841329] xhci_hcd 0000:02:00.0: WARN: short transfer on control ep [ 8966.842079] xhci_hcd 0000:02:00.0: WARN: short transfer on control ep [ 8966.843343] scsi8 : usb-storage 6-3:1.0 [ 8967.847144] scsi 8:0:0:0: Direct-Access SAMSUNG HD204UI 1AQ1 PQ: 0 ANSI: 5 [ 8967.847589] sd 8:0:0:0: Attached scsi generic sg2 type 0 [ 8967.847923] sd 8:0:0:0: [sdb] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 8967.848341] xhci_hcd 0000:02:00.0: WARN: Stalled endpoint [ 8967.850959] sd 8:0:0:0: [sdb] Write Protect is off [ 8967.850963] sd 8:0:0:0: [sdb] Mode Sense: 23 00 00 00 [ 8967.850966] sd 8:0:0:0: [sdb] Assuming drive cache: write through [ 8967.851818] xhci_hcd 0000:02:00.0: WARN: Stalled endpoint [ 8967.852365] sd 8:0:0:0: [sdb] Assuming drive cache: write through [ 8967.852370] sdb: sdb1 [ 8967.871315] xhci_hcd 0000:02:00.0: WARN: Stalled endpoint [ 8967.871853] sd 8:0:0:0: [sdb] Assuming drive cache: write through [ 8967.871856] sd 8:0:0:0: [sdb] Attached SCSI disk [ 8967.950728] xhci_hcd 0000:02:00.0: WARN: Stalled endpoint [ 8967.951355] sd 8:0:0:0: [sdb] Sense Key : Recovered Error [current] [descriptor] [ 8967.951361] Descriptor sense data with sense descriptors (in hex): [ 8967.951363] 72 01 04 1d 00 00 00 0e 09 0c 00 00 00 00 00 00 [ 8967.951375] 00 00 00 00 00 50 [ 8967.951380] sd 8:0:0:0: [sdb] ASC=0x4 ASCQ=0x1d [ 8968.790076] xhci_hcd 0000:02:00.0: HC died; cleaning up [ 8968.790076] usb 6-3: USB disconnect, address 2 [ 8999.008554] scsi 8:0:0:0: [sdb] Unhandled error code [ 8999.008558] scsi 8:0:0:0: [sdb] Result: hostbyte=DID_TIME_OUT driverbyte=DRIVER_OK [ 8999.008562] scsi 8:0:0:0: [sdb] CDB: Read(10): 28 00 74 70 97 39 00 00 3e 00 [ 8999.008573] end_request: I/O error, dev sdb, sector 1953535801 [ 8999.008578] Buffer I/O error on device sdb1, logical block 1953535738 [ 8999.008582] Buffer I/O error on device sdb1, logical block 1953535739 [ 8999.008585] Buffer I/O error on device sdb1, logical block 1953535740 [ 8999.008589] Buffer I/O error on device sdb1, logical block 1953535741 [ 8999.008592] Buffer I/O error on device sdb1, logical block 1953535742 [ 8999.008595] Buffer I/O error on device sdb1, logical block 1953535743 [ 8999.008600] Buffer I/O error on device sdb1, logical block 1953535744 [ 8999.008603] Buffer I/O error on device sdb1, logical block 1953535745 [ 8999.008606] Buffer I/O error on device sdb1, logical block 1953535746 [ 8999.008609] Buffer I/O error on device sdb1, logical block 1953535747 [ 8999.008642] scsi 8:0:0:0: rejecting I/O to offline device [ 8999.008747] scsi 8:0:0:0: [sdb] Unhandled error code [ 8999.008749] scsi 8:0:0:0: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK [ 8999.008752] scsi 8:0:0:0: [sdb] CDB: Read(10): 28 00 74 70 97 77 00 00 3e 00 [ 8999.008760] end_request: I/O error, dev sdb, sector 1953535863 sudo lspci -v 2:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03) (prog-if 30) Physical Slot: 32 Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at fe9fe000 (64-bit, non-prefetchable) [size=8K] Capabilities: [50] Power Management version 3 Capabilities: [70] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [90] MSI-X: Enable- Count=8 Masked- Capabilities: [a0] Express Endpoint, MSI 00 Capabilities: [100] Advanced Error Reporting Capabilities: [140] Device Serial Number ff-ff-ff-ff-ff-ff-ff-ff Capabilities: [150] #18 Kernel driver in use: xhci_hcd Kernel modules: xhci-hcd If I try to put into this controller any USB 2.0, it works fine. But USB 3.0 nope. Any idea?

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• SBUG Session: The Enterprise Cache

  - by EltonStoneman

  [Source: http://geekswithblogs.net/EltonStoneman] I did a session on "The Enterprise Cache" at the UK SOA/BPM User Group yesterday which generated some useful discussion. The proposal was for a dedicated caching layer which all app servers and service providers can hook into, sharing resources and common data. The architecture might end up like this: I'll update this post with a link to the slide deck once it's available. The next session will have Udi Dahan walking through nServiceBus, register on EventBrite if you want to come along. Synopsis Looked at the benefits and drawbacks of app-centric isolated caches, compared to an enterprise-wide shared cache running on dedicated nodes; Suggested issues and risks around caching including staleness of data, resource usage, performance and testing; Walked through a generic service cache implemented as a WCF behaviour – suitable for IIS- or BizTalk-hosted services - which I'll be releasing on CodePlex shortly; Listed common options for cache providers and their offerings. Discussion Cache usage. Different value propositions for utilising the cache: improved performance, isolation from underlying systems (e.g. service output caching can have a TTL large enough to cover downtime), reduced resource impact – CPU, memory, SQL and cost (e.g. caching results of paid-for services). Dedicated cache nodes. Preferred over in-host caching provided latency is acceptable. Depending on cache provider, can offer easy scalability and global replication so cache clients always use local nodes. Restriction of AppFabric Caching to Windows Server 2008 not viewed as a concern. Security. Limited security model in most cache providers. Options for securing cache content suggested as custom implementations. Obfuscating keys and serialized values may mean additional security is not needed. Depending on security requirements and architecture, can ensure cache servers only accessible to cache clients via IPsec. Staleness. Generally thought to be an overrated problem. Thinking in line with eventual consistency, that serving up stale data may not be a significant issue. Good technical arguments support this, although I suspect business users will be harder to persuade. Providers. Positive feedback for AppFabric Caching – speed, configurability and richness of the distributed model making it a good enterprise choice. .NET port of memcached well thought of for performance but lack of replication makes it less suitable for these shared scenarios. Replicated fork – repcached – untried and less active than memcached. NCache also well thought of, but Express version too limited for enterprise scenarios, and commercial versions look costly compared to AppFabric.

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• Fun with Sun Ray, 3D, Oracle VM x86 and SRIOV

  - by wim.coekaerts

  One of the things I like about my job is that I get to play around with stuff and make use of the technologies we work on in my teams. Sort of my own little playground. It allows me to study the products in great detail and put them to use in ways that individual product teams don't always intend them to be used for :) but that makes it fun. I have a lot of this set up at home because... work is sort of hobby and I just like to tinker with it. Anyway, a few weeks ago I was looking at my sun ray rig at home and how well 3D works. Google Earth and some basic opengl tests like glxspheres combined with virtualgl. It resulted in some very cool demos recorded with my little camera (sorry for the crappy quality of the video :-) : OVDC (soft client) on my mac Sun Ray 2FS Never mind the hickups during zoom, that's because I was using the scrollwheel on my mouse and I can't scroll uninterrupted :) Anyway, this is quite cool ! The setup for this was the following : Sun Ray on LAN, Sun Ray Server 5 latest installed on OL5.5 inside a VM running on Oracle VM 2.2 (hardware virt, with a virtual network (vif)) and the virtualgl rendering happened on another box (wopr5) that runs linux on a little atom D520 with an ION2 gpu. So network goes from Sun Ray to Sun Ray Server to wopr5 and back. Given that this is full screen 3D it puts a good amount of load on the network and it's pretty cool that SRS was just a VM :) So, separately, I had written a little blog entry about using sriov and oracle vm a while back. link to sriov blog entry Last night when I came home I wanted to do some more playing around with SRIOV and live migrate. To do this, I wanted to set up a VM with 2 network interfaces, one virtual network (vif) and then one that's one of the SRIOV virtual functions from my network card. Inside the guest they show as eth0 and eth1, and then bond them using a standard linux bonding device (bond0 here) with active active links. The goal here is that on live migrate, we would detach the VF (eth1 in guest in this case), the bond would then just hum along on eth0 (vif) we can live migrate the VM and then on the other server after the migrate completes we re-attach a VF to the VM there and eth1 pops up again and the bond uses both eth0/eth1 to do its work. So, to set this up, I figured, why not use my sun ray server VM because the 3D work generates a nice network load and is very latency/timing sensitive. In the end, I ran glxspheres on my sunray server (vm) displaying on my sun ray 2 fs and while that was running, I did my live migrate test of this vm (unplug pci VF, migrate, reconnect vf) and guess what, it just kept running :) veryyyyyy cool. now, it was supposed to, but it's always nice to see it actually work, for real. Here's a diagram of it. No gimics - just real technology at work ! enjoy :)

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• PASS 13 Dispatches: moving to the cloud

  - by Tony Davis

  PASS Summit 13, Day 1 keynote by Quentin Clarke and we're hearing about “redefiniing mission critical in the cloud”. With a move to the Windows Azure cloud comes the promise of capacity on demand, automatic HA, backups, patching and so on, as well as passing responsibility to MS for managing hardware, upgrades and so on. However, for many databases and applications the best route to the cloud is not necessarily obvious. For most, the path of least resistance is IaaS – SQL Server in a Azure VM. It removes the hardware burden but you still have to manage your databases and implementing HA for SQL Server is your responsibility. Also, scaling up comes at quite a cost – the biggest VM (8 CPU cores, 56 GB RAM, 16 1TB drives with 500 IOPS each) weighs in at over over $4500 per month. With PaaS, in the form of Windows SQL Database, you get a “3-copies replica set” so HA comes out-of the box, and removes the majority of the administration burden, but you are moving your database into a very different environment. For a start, it's a shared environment, with other customers using the same compute nodes in the cluster, and potentially even sharing the same database (multi-tenancy). Unless you pay for SQL DB Premium edition, the resources available for your workload will depends on how nicely others “play” in the shared environment. You'll potentially need to do a lot of tuning, and application rewriting to avoid throttling issues, optimising application-database communication to deal with increased latency between the two, and so on. You'll need aggressive application caching. You'll also need retry logic and to deal with (expected) node failure and the need to reconnect. In Tuesday's PASS Summit pre-con from the SQLCAT team, they spent a lot of time covering some of the telemetric techniques (collect into Azure storage the necessary monitoring data) to perform capacity planning, work out the hotspots and bottlenecks in your cloud applications. Tools like WAD (Windows Azure Diagnostics), performance counters SQL Database DMVs, and others, will be essential. Of course, to truly exploit the vast horizontal scaling that is available from the existence of thousands of compute nodes, you'll also need to need to consider how to “shard” your data so Azure can move it between nodes at will. Finding the right path to the Cloud isn't easy, but it's coming. I spoke to people one year ago who saw no real benefit in trying to move their infrastructure and databases to the cloud, but now at their company, it's the conversation that won't go away. Tony.  

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• Network is not working anymore - Ubuntu 12.04

  - by Jonathan

  Network is not working anymore - Ubuntu 12.04 Hello, I have a problem with my network connection. I have been using the same laptop with Ubuntu and the same connection for more than a year, and suddenly yesterday the connection stopped working (both wireless and wired). I've tested with another computer and the connection is fine (both wireless and wired). I've been reading similar posts but I haven't found a solution yet. I tried a few commands that I'm posting here (my system is in spanish, so I have traslated it to english, maybe the terms are not accurate): grep -i eth /var/log/syslog | tail Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): now managed Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): device state change: unmanaged - unavailable (reason 'managed') [10 20 2] Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): bringing up device. Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): preparing device. Jun 3 18:45:40 vanesa-pc kernel: [ 7351.845743] forcedeth 0000:00:0a.0: irq 41 for MSI/MSI-X Jun 3 18:45:40 vanesa-pc kernel: [ 7351.845984] forcedeth 0000:00:0a.0: eth0: no link during initialization Jun 3 18:45:40 vanesa-pc kernel: [ 7351.847103] ADDRCONF(NETDEV_UP): eth0: link is not ready Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): deactivating device (reason 'managed') [2] Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: Added default wired connection 'Wired connection 1' for /sys/devices/pci0000:00/0000:00:0a.0/net/eth0 Jun 3 18:45:40 vanesa-pc kernel: [ 7351.848817] ADDRCONF(NETDEV_UP): eth0: link is not ready ifconfig -a eth0 Link encap:Ethernet addressHW 00:1b:24:fc:a8:d1 ACTIVE BROADCAST MULTICAST MTU:1500 Metric:1 Packages RX:0 errors:16 lost:0 overruns:0 frame:16 Packages TX:123 errors:0 lost:0 overruns:0 carrier:0 colissions:0 length.tailTX:1000 Bytes RX:0 (0.0 B) TX bytes:26335 (26.3 KB) Interruption:41 Base address: 0x2000 lo Link encap:Local loop Inet address:127.0.0.1 Mask:255.0.0.0 Inet6 address: ::1/128 Scope:Host ACTIVE LOOP WORKING MTU:16436 Metrics:1 Packages RX:1550 errors:0 lost:0 overruns:0 frame:0 Packages TX:1550 errors:0 lost:0 overruns:0 carrier:0 colissions:0 long.tailTX:0 Bytes RX:125312 (125.3 KB) TX bytes:125312 (125.3 KB) iwconfig lo no wireless extensions. eth0 no wireless extensions. sudo lshw -C network *-network description: Ethernet interface product: MCP67 Ethernet manufacturer: NVIDIA Corporation Physical id: a bus information: pci@0000:00:0a.0 logical name: eth0 version: a2 series: 00:1b:24:fc:a8:d1 capacity: 100Mbit/s width: 32 bits clock: 66MHz capacities: pm msi ht bus_master cap_list ethernet physical mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=forcedeth driverversion=0.64 latency=0 link=no maxlatency=20 mingnt=1 multicast=yes port=MII resources: irq:41 memoria:f6288000-f6288fff ioport:30f8(size=8) memoria:f6289c00-f6289cff memoria:f6289800-f628980f lsmod Module Size Used by usbhid 41906 0 hid 77367 1 usbhid rfcomm 38139 0 parport_pc 32114 0 ppdev 12849 0 bnep 17830 2 bluetooth 158438 10 rfcomm,bnep binfmt_misc 17292 1 joydev 17393 0 hp_wmi 13652 0 sparse_keymap 13658 1 hp_wmi nouveau 708198 3 ttm 65344 1 nouveau drm_kms_helper 45466 1 nouveau drm 197692 5 nouveau,ttm,drm_kms_helper i2c_algo_bit 13199 1 nouveau psmouse 87213 0 mxm_wmi 12859 1 nouveau serio_raw 13027 0 k8temp 12905 0 i2c_nforce2 12906 0 wmi 18744 2 hp_wmi,mxm_wmi video 19068 1 nouveau mac_hid 13077 0 lp 17455 0 parport 40930 3 parport_pc,ppdev,lp forcedeth 58096 0 Let me know if I can give you more information. Thank you very much in advance, Jonathan

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• Back-sliding into Unmanaged Code

  - by Laila

  It is difficult to write about Microsoft's ambivalence to .NET without mentioning clichés about dog food.  In case you've been away a long time, you'll remember that Microsoft surprised everyone with the speed and energy with which it introduced and evangelised the .NET Framework for managed code. There was good reason for this. Once it became obvious to all that it had sleepwalked into third place as a provider of development languages, behind Borland and Sun, it reacted quickly to attract the best talent in the industry to produce a windows version of the Java runtime, with Bounds-checking, Automatic Garbage collection, structures exception handling and common data types. To develop applications for this managed runtime, it produced several excellent languages, and more are being provided. The only thing Microsoft ever got wrong was to give it a stupid name. The logical step for Microsoft would be to base the entire operating system on the .NET framework, and to re-engineer its own applications. In 2002, Bill Gates, then Microsoft Chairman and Chief Software Architect said about their plans for .NET, "This is a long-term approach. These things don't happen overnight." Now, eight years later, we're still waiting for signs of the 'long-term approach'. Microsoft's vision of an entirely managed operating system has subsided since the Vista fiasco, but stays alive yet dormant as Midori, still being developed by Microsoft Research. This is an Internet-centric fork of the singularity operating system, a research project started in 2003 to build a highly-dependable operating system in which the kernel, device drivers, and applications are all written in managed code. Midori is predicated on the prevalence of connected systems, with provisions for distributed concurrency where application components exist 'in the cloud', and supports a programming model that can tolerate cancellation, intermittent connectivity and latency. It features an entirely new security model that sandboxes applications for increased security. So have Microsoft converted its existing applications to the .NET framework? It seems not. What Windows applications can run on Mono? Very few, it seems. We all thought that .NET spelt the end of DLL Hell and the need for COM interop, but it looks as if Bill Gates' idea of 'not overnight' might stretch to a decade or more. The Operating System has shown only minimal signs of migrating to .NET. Even where the use of .NET has come to dominate, when used for server applications with IIS, IIS itself is still entirely developed in unmanaged code. This is an irritation to Microsoft's greatest supporters who committed themselves fully to the NET framework, only to find parts of the Ambivalent Microsoft Empire quietly backsliding into unmanaged code and the awful C++. It is a strategic mistake that the invigorated Apple didn't make with the Mac OS X Architecture. Cheers, Laila

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• What does the `dmesg` error: "composite sync not supported" mean?

  - by M. Tibbits

  Question: I see [ 20.473125] composite sync not supported and several such entries when I run dmesg. What do they mean? Background: I'm trying to debug a problem where my laptop won't suspend. Since acpi seems happy and I can suspend easily from the command line, I've turned to tracking down all boot-up errors/warnings. So I run dmesg | grep not and, amongst other shtuff, I get: 728:[ 17.267120] composite sync not supported 733:[ 18.009061] composite sync not supported 740:[ 18.159289] registered panic notifier 749:[ 18.162500] vga16fb: not registering due to another framebuffer present 757:[ 18.598251] composite sync not supported 776:[ 20.473125] composite sync not supported 777:[ 20.932266] composite sync not supported 778:[ 28.350231] composite sync not supported 779:[ 28.924913] composite sync not supported 780:[ 35.480658] composite sync not supported And the full log for the few lines right around that first appearance (line 728) is listed at the bottom of my post (I'd happily include anything else). Any ideas what could be causing this? I've read several sites: Ubuntuforums #1 IRC Chat #1 One post talks about ??Adobe flash?? causing this error? Some others also suggest that it might be an nvidia related problem, but I've got a Dell Latitude D630 with an integrated Intel graphics -- so nvidia isn't the problem. [ 17.207142] phy0: Selected rate control algorithm 'minstrel' [ 17.207833] Registered led device: b43-phy0::tx [ 17.207849] Registered led device: b43-phy0::rx [ 17.207865] Registered led device: b43-phy0::radio [ 17.207927] Broadcom 43xx driver loaded [ Features: PL, Firmware-ID: FW13 ] [ 17.267120] composite sync not supported [ 17.415795] EXT4-fs (sda2): mounted filesystem with ordered data mode [ 17.602131] [drm] initialized overlay support [ 17.620201] input: DualPoint Stick as /devices/platform/i8042/serio1/input/input7 [ 17.641192] input: AlpsPS/2 ALPS DualPoint TouchPad as /devices/platform/i8042/serio1/input/input8 [ 18.009061] composite sync not supported [ 18.106042] pcmcia_socket pcmcia_socket0: cs: IO port probe 0x100-0x3af: clean. [ 18.108115] pcmcia_socket pcmcia_socket0: cs: IO port probe 0x3e0-0x4ff: clean. [ 18.108941] pcmcia_socket pcmcia_socket0: cs: IO port probe 0x820-0x8ff: clean. [ 18.109676] pcmcia_socket pcmcia_socket0: cs: IO port probe 0xc00-0xcf7: clean. [ 18.110356] pcmcia_socket pcmcia_socket0: cs: IO port probe 0xa00-0xaff: clean. [ 18.159286] fb0: inteldrmfb frame buffer device [ 18.159289] registered panic notifier [ 18.160218] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/LNXVIDEO:01/input/input9 [ 18.160286] ACPI: Video Device [VID1] (multi-head: yes rom: no post: no) [ 18.160334] ACPI Warning for \_SB_.PCI0.VID2._DOD: Return Package has no elements (empty) (20090903/nspredef-433) [ 18.160432] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/LNXVIDEO:02/input/input10 [ 18.160491] ACPI: Video Device [VID2] (multi-head: yes rom: no post: no) [ 18.160539] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0 [ 18.162494] vga16fb: initializing [ 18.162497] vga16fb: mapped to 0xc00a0000 [ 18.162500] vga16fb: not registering due to another framebuffer present [ 18.176091] HDA Intel 0000:00:1b.0: PCI INT A -> GSI 21 (level, low) -> IRQ 21 [ 18.176123] HDA Intel 0000:00:1b.0: setting latency timer to 64 [ 18.285752] input: HDA Digital PCBeep as /devices/pci0000:00/0000:00:1b.0/input/input11 [ 18.312497] input: HDA Intel Mic at Ext Left Jack as /devices/pci0000:00/0000:00:1b.0/sound/card0/input12 [ 18.312586] input: HDA Intel HP Out at Ext Left Jack as /devices/pci0000:00/0000:00:1b.0/sound/card0/input13 [ 18.328043] usbcore: registered new interface driver ndiswrapper [ 18.460909] Console: switching to colour frame buffer device 180x56 [ 18.598251] composite sync not supported

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