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• SVN Server not responding

  - by Rob Forrest

  I've been bashing my head against a wall with this one all day and I would greatly appreciate a few more eyes on the problem at hand. We have an in-house SVN Server that contains all live and development code for our website. Our live server can connect to this and get updates from the repository. This was all working fine until we migrated the SVN Server from a physical machine to a vSphere VM. Now, for some reason that continues to fathom me, we can no longer connect to the SVN Server. The SVN Server runs CentOS 6.2, Apache and SVN 1.7.2. SELinux is well and trully disabled and the problem remains when iptables is stopped. Our production server does run an older version of CentOS and SVN but the same system worked previously so I don't think that this is the issue. Of note, if I have iptables enabled, using service iptables status, I can see a single packet coming in and being accepted but the production server simply hangs on any svn command. If I give up waiting and do a CTRL-C to break the process I get a "could not connect to server". To me it appears to be something to do with the SVN Server rejecting external connections but I have no idea how this would happen. Any thoughts on what I can try from here? Thanks, Rob Edit: Network topology Production server sits externally to our in-house SVN server. Our IPCop (?) firewall allows connections from it (and it alone) on port 80 and passes the connection to the SVN Server. The hardware is all pretty decent and I don't doubt that its doing its job correctly, especially as iptables is seeing the new connections. subversion.conf (in /etc/httpd/conf.d) LoadModule dav_svn_module modules/mod_dav_svn.so <Location /repos> DAV svn SVNPath /var/svn/repos <LimitExcept PROPFIND OPTIONS REPORT> AuthType Basic AuthName "SVN Server" AuthUserFile /var/svn/svn-auth Require valid-user </LimitExcept> </Location> ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:5F:C8:3A inet addr:172.16.0.14 Bcast:172.16.0.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe5f:c83a/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:32317 errors:0 dropped:0 overruns:0 frame:0 TX packets:632 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2544036 (2.4 MiB) TX bytes:143207 (139.8 KiB) netstat -lntp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1484/mysqld tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1135/rpcbind tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1351/sshd tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 1230/cupsd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1575/master tcp 0 0 0.0.0.0:58401 0.0.0.0:* LISTEN 1153/rpc.statd tcp 0 0 0.0.0.0:5672 0.0.0.0:* LISTEN 1626/qpidd tcp 0 0 :::139 :::* LISTEN 1678/smbd tcp 0 0 :::111 :::* LISTEN 1135/rpcbind tcp 0 0 :::80 :::* LISTEN 1615/httpd tcp 0 0 :::22 :::* LISTEN 1351/sshd tcp 0 0 ::1:631 :::* LISTEN 1230/cupsd tcp 0 0 ::1:25 :::* LISTEN 1575/master tcp 0 0 :::445 :::* LISTEN 1678/smbd tcp 0 0 :::56799 :::* LISTEN 1153/rpc.statd iptables --list -v -n (when iptables is stopped) Chain INPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination iptables --list -v -n (when iptables is running, after one attempted svn connection) Chain INPUT (policy ACCEPT 68 packets, 6561 bytes) pkts bytes target prot opt in out source destination 19 1304 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22 1 60 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:80 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:80 0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 state NEW udp dpt:80 Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination Chain OUTPUT (policy ACCEPT 17 packets, 1612 bytes) pkts bytes target prot opt in out source destination tcpdump 17:08:18.455114 IP 'production server'.43255 > 'svn server'.local.http: Flags [S], seq 3200354543, win 5840, options [mss 1380,sackOK,TS val 2011458346 ecr 0,nop,wscale 7], length 0 17:08:18.455169 IP 'svn server'.local.http > 'production server'.43255: Flags [S.], seq 629885453, ack 3200354544, win 14480, options [mss 1460,sackOK,TS val 816478 ecr 2011449346,nop,wscale 7], length 0 17:08:19.655317 IP 'svn server'.local.http > 'production server'k.43255: Flags [S.], seq 629885453, ack 3200354544, win 14480, options [mss 1460,sackOK,TS val 817679 ecr 2011449346,nop,wscale 7], length 0

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• Improving TCP performance over a gigabit network lots of connections and high traffic for storage and streaming services

  - by Linux Guy

  I have two servers, Both servers hardware Specification are Processor : Dual Processor RAM : over 128 G.B Hard disk : SSD Hard disk Outging Traffic bandwidth : 3 Gbps network cards speed : 10 Gbps Server A : for Encoding videos Server B : for storage videos andstream videos over web interface like youtube The inbound bandwidth between two servers is 10Gbps , the outbound bandwidth internet bandwidth is 500Mpbs Both servers using public ip addresses in public and private network Both servers transfer and connection on nginx port , and the server B used for streaming media , like youtube stream videos Both servers in same network , when i do ping from Server A to Server B i got high time latency above 1.0ms , the time range time=52.7 ms to time=215.7 ms - This is the output of iftop utility 353Mb 707Mb 1.04Gb 1.38Gb 1.73Gb mqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqq server.example.com => ip.address 6.36Mb 4.31Mb 1.66Mb <= 158Kb 94.8Kb 35.1Kb server.example.com => ip.address 1.23Mb 4.28Mb 1.12Mb <= 17.1Kb 83.5Kb 21.9Kb server.example.com => ip.address 395Kb 3.89Mb 1.07Mb <= 6.09Kb 109Kb 28.6Kb server.example.com => ip.address 4.55Mb 3.83Mb 1.04Mb <= 55.6Kb 45.4Kb 13.0Kb server.example.com => ip.address 649Kb 3.38Mb 1.47Mb <= 9.00Kb 38.7Kb 16.7Kb server.example.com => ip.address 5.00Mb 3.32Mb 1.80Mb <= 65.7Kb 55.1Kb 29.4Kb server.example.com => ip.address 387Kb 3.13Mb 1.06Mb <= 18.4Kb 39.9Kb 15.0Kb server.example.com => ip.address 3.27Mb 3.11Mb 1.01Mb <= 81.2Kb 64.5Kb 20.9Kb server.example.com => ip.address 1.75Mb 3.08Mb 2.72Mb <= 16.6Kb 35.6Kb 32.5Kb server.example.com => ip.address 1.75Mb 2.90Mb 2.79Mb <= 22.4Kb 32.6Kb 35.6Kb server.example.com => ip.address 3.03Mb 2.78Mb 1.82Mb <= 26.6Kb 27.4Kb 20.2Kb server.example.com => ip.address 2.26Mb 2.66Mb 1.36Mb <= 51.7Kb 49.1Kb 24.4Kb server.example.com => ip.address 586Kb 2.50Mb 1.03Mb <= 4.17Kb 26.1Kb 10.7Kb server.example.com => ip.address 2.42Mb 2.49Mb 2.44Mb <= 31.6Kb 29.7Kb 29.9Kb server.example.com => ip.address 2.41Mb 2.46Mb 2.41Mb <= 26.4Kb 24.5Kb 23.8Kb server.example.com => ip.address 2.37Mb 2.39Mb 2.40Mb <= 28.9Kb 27.0Kb 28.5Kb server.example.com => ip.address 525Kb 2.20Mb 1.05Mb <= 7.03Kb 26.0Kb 12.8Kb qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq TX: cum: 102GB peak: 1.65Gb rates: 1.46Gb 1.44Gb 1.48Gb RX: 1.31GB 24.3Mb 19.5Mb 18.9Mb 20.0Mb TOTAL: 103GB 1.67Gb 1.48Gb 1.46Gb 1.50Gb I check the transfer speed using iperf utility From Server A to Server B # iperf -c 0.0.0.2 -p 8777 ------------------------------------------------------------ Client connecting to 0.0.0.2, TCP port 8777 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 3] local 0.0.0.1 port 38895 connected with 0.0.0.2 port 8777 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.8 sec 528 KBytes 399 Kbits/sec My Current Connections in Server B # netstat -an|grep ":8777"|awk '/tcp/ {print $6}'|sort -nr| uniq -c 2072 TIME_WAIT 28 SYN_RECV 1 LISTEN 189 LAST_ACK 139 FIN_WAIT2 373 FIN_WAIT1 3381 ESTABLISHED 34 CLOSING Server A Network Card Information Settings for eth0: Supported ports: [ TP ] Supported link modes: 100baseT/Full 1000baseT/Full 10000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Advertised link modes: 10000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: Yes Speed: 10000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: external Auto-negotiation: on MDI-X: Unknown Supports Wake-on: d Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes Server B Network Card Information Settings for eth2: Supported ports: [ FIBRE ] Supported link modes: 10000baseT/Full Supported pause frame use: No Supports auto-negotiation: No Advertised link modes: 10000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: No Speed: 10000Mb/s Duplex: Full Port: Direct Attach Copper PHYAD: 0 Transceiver: external Auto-negotiation: off Supports Wake-on: d Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes ifconfig server A eth0 Link encap:Ethernet HWaddr 00:25:90:ED:9E:AA inet addr:0.0.0.1 Bcast:0.0.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1202795665 errors:0 dropped:64334 overruns:0 frame:0 TX packets:2313161968 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:893413096188 (832.0 GiB) TX bytes:3360949570454 (3.0 TiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2207544 errors:0 dropped:0 overruns:0 frame:0 TX packets:2207544 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:247769175 (236.2 MiB) TX bytes:247769175 (236.2 MiB) ifconfig Server B eth2 Link encap:Ethernet HWaddr 00:25:90:82:C4:FE inet addr:0.0.0.2 Bcast:0.0.0.2 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:39973046980 errors:0 dropped:1828387600 overruns:0 frame:0 TX packets:69618752480 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:3013976063688 (2.7 TiB) TX bytes:102250230803933 (92.9 TiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:1049495 errors:0 dropped:0 overruns:0 frame:0 TX packets:1049495 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:129012422 (123.0 MiB) TX bytes:129012422 (123.0 MiB) Netstat -i on Server B # netstat -i Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth2 9000 0 42098629968 0 2131223717 0 73698797854 0 0 0 BMRU lo 65536 0 1077908 0 0 0 1077908 0 0 0 LRU I Turn up send/receive buffers on the network card to 2048 and problem still persist I increase the MTU for server A and problem still persist and i increase the MTU for server B for better connectivity and transfer speed but it couldn't transfer at all The problem is : as you can see from iperf utility, the transfer speed from server A to server B slow when i restart network service in server B the transfer in server A at full speed, after 2 minutes , it's getting slow How could i troubleshoot slow speed issue and fix it in server B ? Notice : if there any other commands i should execute in servers for more information, so it might help resolve the problem , let me know in comments

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• xen domUs crashes or unavailability

  - by Rush

  I've xen server with 8 domU. Server is Xeon E31270 with 16gb ram. I think it is enough for 8 machines. Sometimes domU's crashes and i can't figure out the reason. After crash i can connect to console and there is somthing like this: Oct 8 22:20:49 server kernel: [30892.320780] lowmem_reserve[]: 0 0 0 0 Oct 8 22:20:49 server kernel: [30892.320790] Node 0 DMA: 10*4kB 3*8kB 13*16kB 10*32kB 7*64kB 3*128kB 2*256kB 2*512kB 1*1024kB 2*2048kB 0*4096kB = 8080kB Oct 8 22:20:49 server kernel: [30892.320817] Node 0 DMA32: 648*4kB 2*8kB 1*16kB 0*32kB 1*64kB 0*128kB 0*256kB 0*512kB 1*1024kB 1*2048kB 0*4096kB = 5760kB Oct 8 22:20:49 server kernel: [30892.320842] 1491 total pagecache pages Oct 8 22:20:49 server kernel: [30892.320847] 0 pages in swap cache Oct 8 22:20:49 server kernel: [30892.320852] Swap cache stats: add 0, delete 0, find 0/0 Oct 8 22:20:49 server kernel: [30892.320858] Free swap = 0kB Oct 8 22:20:49 server kernel: [30892.320862] Total swap = 0kB Oct 8 22:20:49 server kernel: [30892.324024] 524288 pages RAM Oct 8 22:20:49 server kernel: [30892.324024] 11010 pages reserved Oct 8 22:20:49 server kernel: [30892.324024] 424467 pages shared Oct 8 22:20:49 server kernel: [30892.324024] 503538 pages non-shared Oct 8 22:20:49 server kernel: [30892.330308] apache2 invoked oom-killer: gfp_mask=0x200da, order=0, oom_adj=0 Oct 8 22:20:49 server kernel: [30892.330322] apache2 cpuset=/ mems_allowed=0 Oct 8 22:20:49 server kernel: [30892.330330] Pid: 23938, comm: apache2 Not tainted 2.6.32-5-xen-amd64 #1 Oct 8 22:20:49 server kernel: [30892.330337] Call Trace: Oct 8 22:20:49 server kernel: [30892.330349] [<ffffffff810b7180>] ? oom_kill_process+0x7f/0x23f Oct 8 22:20:49 server kernel: [30892.330358] [<ffffffff810b76a4>] ? __out_of_memory+0x12a/0x141 Oct 8 22:20:49 server kernel: [30892.330367] [<ffffffff810b77fb>] ? out_of_memory+0x140/0x172 Oct 8 22:20:49 server kernel: [30892.330376] [<ffffffff810bb59c>] ? __alloc_pages_nodemask+0x4e5/0x5f5 Oct 8 22:20:49 server kernel: [30892.330385] [<ffffffff810cc224>] ? do_wp_page+0x386/0x707 Oct 8 22:20:49 server kernel: [30892.330395] [<ffffffff8100c3a5>] ? __raw_callee_save_xen_pud_val+0x11/0x1e Oct 8 22:20:49 server kernel: [30892.330404] [<ffffffff8100c369>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e Oct 8 22:20:49 server kernel: [30892.330412] [<ffffffff810cdfc7>] ? handle_mm_fault+0x7aa/0x80f Oct 8 22:20:49 server kernel: [30892.330422] [<ffffffff8130f906>] ? do_page_fault+0x2e0/0x2fc Oct 8 22:20:49 server kernel: [30892.330433] [<ffffffff8130d7a5>] ? page_fault+0x25/0x30 Oct 8 22:20:49 server kernel: [30892.330439] Mem-Info: Oct 8 22:20:49 server kernel: [30892.330443] Node 0 DMA per-cpu: Oct 8 22:20:49 server kernel: [30892.330450] CPU 0: hi: 0, btch: 1 usd: 0 Oct 8 22:20:49 server kernel: [30892.330463] CPU 1: hi: 0, btch: 1 usd: 0 Oct 8 22:20:49 server kernel: [30892.330466] Node 0 DMA32 per-cpu: Oct 8 22:20:49 server kernel: [30892.330469] CPU 0: hi: 186, btch: 31 usd: 0 Oct 8 22:20:49 server kernel: [30892.330472] CPU 1: hi: 186, btch: 31 usd: 60 Oct 8 22:20:49 server kernel: [30892.330476] active_anon:342076 inactive_anon:115398 isolated_anon:0 Oct 8 22:20:49 server kernel: [30892.330477] active_file:268 inactive_file:481 isolated_file:0 Oct 8 22:20:49 server kernel: [30892.330477] unevictable:1125 dirty:2 writeback:13 unstable:0 Oct 8 22:20:49 server kernel: [30892.330478] free:3410 slab_reclaimable:1718 slab_unreclaimable:6946 Oct 8 22:20:49 server kernel: [30892.330478] mapped:899 shmem:113 pagetables:35697 bounce:0 Oct 8 22:20:49 server kernel: [30892.330502] Node 0 DMA free:8036kB min:32kB low:40kB high:48kB active_anon:1144kB inactive_anon:1268kB active_file:8kB inactive_file:8kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:11792kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:224kB kernel_stack:16kB pagetables:1228kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no Oct 8 22:20:49 server kernel: [30892.330518] lowmem_reserve[]: 0 2004 2004 2004 Oct 8 22:20:49 server kernel: [30892.330523] Node 0 DMA32 free:5604kB min:5708kB low:7132kB high:8560kB active_anon:1367160kB inactive_anon:460324kB active_file:1064kB inactive_file:1916kB unevictable:4500kB isolated(anon):0kB isolated(file):0kB present:2052320kB mlocked:4500kB dirty:8kB writeback:52kB mapped:3600kB shmem:452kB slab_reclaimable:6872kB slab_unreclaimable:27560kB kernel_stack:3528kB pagetables:141560kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:992 all_unreclaimable? no Oct 8 22:20:49 server kernel: [30892.330539] lowmem_reserve[]: 0 0 0 0 Oct 8 22:20:49 server kernel: [30892.330544] Node 0 DMA: 1*4kB 2*8kB 13*16kB 10*32kB 7*64kB 3*128kB 2*256kB 2*512kB 1*1024kB 2*2048kB 0*4096kB = 8036kB Oct 8 22:20:49 server kernel: [30892.330579] Node 0 DMA32: 609*4kB 2*8kB 1*16kB 0*32kB 1*64kB 0*128kB 0*256kB 0*512kB 1*1024kB 1*2048kB 0*4096kB = 5604kB Oct 8 22:20:49 server kernel: [30892.330605] 1522 total pagecache pages Oct 8 22:20:49 server kernel: [30892.330610] 0 pages in swap cache Oct 8 22:20:49 server kernel: [30892.330615] Swap cache stats: add 0, delete 0, find 0/0 Oct 8 22:20:49 server kernel: [30892.330621] Free swap = 0kB Oct 8 22:20:49 server kernel: [30892.330625] Total swap = 0kB Oct 8 22:20:49 server kernel: [30892.333018] 524288 pages RAM Oct 8 22:20:49 server kernel: [30892.333018] 11010 pages reserved Oct 8 22:20:49 server kernel: [30892.333018] 424367 pages shared Oct 8 22:20:49 server kernel: [30892.333018] 503658 pages non-shared Seems like there isn't enough memory for this domU. But there is no any memory problems reported in munin monitoring: As you see system uses around 0.2G and 1G is available. So my question is: Is it xen specific problem, that real memory usage and memory usage that shows munin are different (I've never seen such problems oh real hardware machines)? Or maybe it is just monitoring problem, that can't catch moment when there is unusual high load and domU go down? And how I can to defeat this problem? it is really annoying to catch messages in e-mail that domU went down. Btw, such situation was when domU had 2G memory.

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• ESXi v5.5 is having random crashes

  - by Darkmage

  HW: Type: HP Proliant ML350 G5 RAM 22GB CPU 1 x Intel Xenon E5405 2.00GHz OP: ESXi 5.5 just updated from 5.1 to try and fix the crashes occurring on ESXi 5.1 on same hardware. I'm trying to find the error on why one of our servers is crashing, it has had two lock ups in 24 hours now. The internal error light on the front is blinking red, on the inside only "#5 and #6 page 76 manual" the "Processor 2" light "amber" and the "Power" light "green" is shining. in the logs the only errors i can see in the relevant time frame is in log under. Is this the reason? or is there anything else i can do to try and log/locate the error. from zcat syslog.6.gz | less 2014-05-26T11:55:47Z sfcbd[35064]: Error opening socket pair for getProviderContext: Too many open files 2014-05-26T11:55:47Z sfcbd[35064]: Failed to set recv timeout (30) for socket -1. Errno = 9 2014-05-26T11:55:47Z sfcbd[35064]: Failed to set timeout for local socket (e.g. provider) 2014-05-26T11:55:47Z sfcbd[35064]: spGetMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:55:47Z sfcbd[35064]: rcvMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:55:47Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:47Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:47Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:47Z sfcbd[35064]: Error opening socket pair for getProviderContext: Too many open files 2014-05-26T11:55:47Z sfcbd[35064]: Failed to set recv timeout (30) for socket -1. Errno = 9 2014-05-26T11:55:47Z sfcbd[35064]: Failed to set timeout for local socket (e.g. provider) 2014-05-26T11:55:47Z sfcbd[35064]: spGetMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:55:47Z sfcbd[35064]: rcvMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:55:47Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:47Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:47Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:53Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:55:57Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:01Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:04Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:15Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:17Z sfcbd[35064]: Error opening socket pair for getProviderContext: Too many open files 2014-05-26T11:56:17Z sfcbd[35064]: Failed to set recv timeout (30) for socket -1. Errno = 9 2014-05-26T11:56:17Z sfcbd[35064]: Failed to set timeout for local socket (e.g. provider) 2014-05-26T11:56:17Z sfcbd[35064]: spGetMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:56:17Z sfcbd[35064]: rcvMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:56:17Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:17Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:17Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:17Z sfcbd[35064]: Error opening socket pair for getProviderContext: Too many open files 2014-05-26T11:56:17Z sfcbd[35064]: Failed to set recv timeout (30) for socket -1. Errno = 9 2014-05-26T11:56:17Z sfcbd[35064]: Failed to set timeout for local socket (e.g. provider) 2014-05-26T11:56:17Z sfcbd[35064]: spGetMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:56:17Z sfcbd[35064]: rcvMsg receiving from -1 35064-9 Bad file descriptor 2014-05-26T11:56:17Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:17Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:17Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:23Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:27Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:31Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:34Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:34Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:34Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:34Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:34Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:44Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:44Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:44Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:44Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:46Z sfcb-ProviderManager[34828]: SendMsg sending to 1 34828-9 Bad file descriptor 2014-05-26T11:56:48Z sfcbd[35064]: Error opening socket pair for getProviderContext: Too many open files -- manual

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• dual boot install--no GRUB

  - by Jim Syyap

  My computer recently had a hardware upgrade and now runs on Windows 7. I decided to install Ubuntu 11.04 as dual boot using the ISO I got from ubuntu.com downloaded onto my USB stick. Restarting with the USB stick, I was able to install Ubuntu 11.04 choosing the option: Install Ubuntu 11.04 side by side with Windows 7 (or something like that). No errors were encountered on installation. However on restarting, there was no GRUB; the system went straight into Windows 7. Looking for answers, I found these: http://essayboard.com/2011/07/12/how-to-dual-boot-ubuntu-11-04-and-windows-7-the-traditional-way-through-grub-2/ http://ubuntuforums.org/showthread.php?t=1774523 Following their instructions, I got: Boot Info Script 0.60 from 17 May 2011 ============================= Boot Info Summary: =============================== => Windows is installed in the MBR of /dev/sda. => Syslinux MBR (3.61-4.03) is installed in the MBR of /dev/sdb. => Grub2 (v1.99) is installed in the MBR of /dev/sdc and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos7)/boot/grub on this drive. sda1: __________________________________________________ ________________________ File system: ntfs Boot sector type: Windows Vista/7 Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: /grldr /bootmgr /Boot/BCD /grldr sda2: __________________________________________________ ________________________ File system: ntfs Boot sector type: Windows Vista/7 Boot sector info: No errors found in the Boot Parameter Block. Operating System: Windows 7 Boot files: /Windows/System32/winload.exe sdb1: __________________________________________________ ________________________ File system: vfat Boot sector type: SYSLINUX 4.02 debian-20101016 ...........>...r>....... ......0...~.k...~...f...M.f.f....f..8~....>2} Boot sector info: Syslinux looks at sector 1437504 of /dev/sdb1 for its second stage. SYSLINUX is installed in the directory. The integrity check of the ADV area failed. According to the info in the boot sector, sdb1 starts at sector 0. But according to the info from fdisk, sdb1 starts at sector 62. Operating System: Boot files: /boot/grub/grub.cfg /syslinux/syslinux.cfg /ldlinux.sys sdc1: __________________________________________________ ________________________ File system: ntfs Boot sector type: Windows XP Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: sdc2: __________________________________________________ ________________________ File system: Extended Partition Boot sector type: - Boot sector info: sdc5: __________________________________________________ ________________________ File system: swap Boot sector type: - Boot sector info: sdc6: __________________________________________________ ________________________ File system: swap Boot sector type: - Boot sector info: sdc7: __________________________________________________ ________________________ File system: ext4 Boot sector type: - Boot sector info: Operating System: Ubuntu 11.04 Boot files: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img sdc8: __________________________________________________ ________________________ File system: swap Boot sector type: - Boot sector info: Going back into Ubuntu and running sudo fdisk -l , I got these: ubuntu@ubuntu:~$ sudo fdisk -l Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 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: 0x0002f393 Device Boot Start End Blocks Id System /dev/sda1 * 1 13 102400 7 HPFS/NTFS Partition 1 does not end on cylinder boundary. /dev/sda2 13 19458 156185600 7 HPFS/NTFS Disk /dev/sdb: 2011 MB, 2011168768 bytes 62 heads, 62 sectors/track, 1021 cylinders Units = cylinders of 3844 * 512 = 1968128 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000f2ab9 Device Boot Start End Blocks Id System /dev/sdb1 * 1 1021 1962331 c W95 FAT32 (LBA) Disk /dev/sdc: 1000.2 GB, 1000202043392 bytes 255 heads, 63 sectors/track, 121600 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: 0x00261ddd Device Boot Start End Blocks Id System /dev/sdc1 * 1 60657 487222656+ 7 HPFS/NTFS /dev/sdc2 60657 121600 489527681 5 Extended /dev/sdc5 120563 121600 8337703+ 82 Linux swap / Solaris /dev/sdc6 120073 120562 3930112 82 Linux swap / Solaris /dev/sdc7 60657 119584 473328640 83 Linux /dev/sdc8 119584 120072 3923968 82 Linux swap / Solaris Should I proceed and do the following? Assuming Ubuntu 11.04 was installed on device sdb1, do this: sudo mount /dev/sdb1 /mnt Then do this: sudo grub-install--root-directory=/mnt /dev/sdb Notice there are two dashes in front of the root directory, and I'm not using sdb1 but sdb. Since the command in step 15 had reinstalled Grub 2, now we need to unmount the /mnt (i.e. sdb1) to clean up. Do this: sudo umount /mnt Reboot and remove Ubuntu 11.04 CD/DVD from disk tray. Log into Ubuntu 11.04 (you have no choice but it will make you log into Ubuntu 11.04 at this point). Open up a terminal in Ubuntu 11.04 (using real installation, not live CD/DVD). Execute this command: sudo update-grub Reboot the machine.

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• e2fsck extremly slow, although enough memory exists

  - by kaefert

  I've got this external USB-Disk: kaefert@blechmobil:~$ lsusb -s 2:3 Bus 002 Device 003: ID 0bc2:3320 Seagate RSS LLC As can be seen in this dmesg output, there are some problems that prevents that disk from beeing mounted: kaefert@blechmobil:~$ dmesg | grep sdb [ 114.474342] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.475089] sd 5:0:0:0: [sdb] Write Protect is off [ 114.475092] sd 5:0:0:0: [sdb] Mode Sense: 43 00 00 00 [ 114.475959] sd 5:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 114.477093] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.501649] sdb: sdb1 [ 114.502717] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.504354] sd 5:0:0:0: [sdb] Attached SCSI disk [ 116.804408] EXT4-fs (sdb1): ext4_check_descriptors: Checksum for group 3976 failed (47397!=61519) [ 116.804413] EXT4-fs (sdb1): group descriptors corrupted! So I went and fired up my favorite partition manager - gparted, and told it to verify and repair the partition sdb1. This made gparted call e2fsck (version 1.42.4 (12-Jun-2012)) e2fsck -f -y -v /dev/sdb1 Although gparted called e2fsck with the "-v" option, sadly it doesn't show me the output of my e2fsck process (bugreport https://bugzilla.gnome.org/show_bug.cgi?id=467925 ) I started this whole thing on Sunday (2012-11-04_2200) evening, so about 48 hours ago, this is what htop says about it now (2012-11-06-1900): PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command 3704 root 39 19 1560M 1166M 768 R 98.0 19.5 42h56:43 e2fsck -f -y -v /dev/sdb1 Now I found a few posts on the internet that discuss e2fsck running slow, for example: http://gparted-forum.surf4.info/viewtopic.php?id=13613 where they write that its a good idea to see if the disk is just that slow because maybe its damaged, and I think these outputs tell me that this is not the case in my case: kaefert@blechmobil:~$ sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 3562 MB in 2.00 seconds = 1783.29 MB/sec Timing buffered disk reads: 82 MB in 3.01 seconds = 27.26 MB/sec kaefert@blechmobil:~$ sudo hdparm /dev/sdb /dev/sdb: multcount = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 364801/255/63, sectors = 5860533160, start = 0 However, although I can read quickly from that disk, this disk speed doesn't seem to be used by e2fsck, considering tools like gkrellm or iotop or this: kaefert@blechmobil:~$ iostat -x Linux 3.2.0-2-amd64 (blechmobil) 2012-11-06 _x86_64_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 14,24 47,81 14,63 0,95 0,00 22,37 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sda 0,59 8,29 2,42 5,14 43,17 160,17 53,75 0,30 39,80 8,72 54,42 3,95 2,99 sdb 137,54 5,48 9,23 0,20 587,07 22,73 129,35 0,07 7,70 7,51 16,18 2,17 2,04 Now I researched a little bit on how to find out what e2fsck is doing with all that processor time, and I found the tool strace, which gives me this: kaefert@blechmobil:~$ sudo strace -p3704 lseek(4, 41026998272, SEEK_SET) = 41026998272 write(4, "\212\354K[_\361\3nl\212\245\352\255jR\303\354\312Yv\334p\253r\217\265\3567\325\257\3766"..., 4096) = 4096 lseek(4, 48404766720, SEEK_SET) = 48404766720 read(4, "\7t\260\366\346\337\304\210\33\267j\35\377'\31f\372\252\ffU\317.y\211\360\36\240c\30`\34"..., 4096) = 4096 lseek(4, 41027002368, SEEK_SET) = 41027002368 write(4, "\232]7Ws\321\352\t\1@[+5\263\334\276{\343zZx\352\21\316`1\271[\202\350R`"..., 4096) = 4096 lseek(4, 48404770816, SEEK_SET) = 48404770816 read(4, "\17\362r\230\327\25\346//\210H\v\311\3237\323K\304\306\361a\223\311\324\272?\213\tq \370\24"..., 4096) = 4096 lseek(4, 41027006464, SEEK_SET) = 41027006464 write(4, "\367yy>x\216?=\324Z\305\351\376&\25\244\210\271\22\306}\276\237\370(\214\205G\262\360\257#"..., 4096) = 4096 lseek(4, 48404774912, SEEK_SET) = 48404774912 read(4, "\365\25\0\21|T\0\21}3t_\272\373\222k\r\177\303\1\201\261\221$\261B\232\3142\21U\316"..., 4096) = 4096 ^CProcess 3704 detached around 16 of these lines every second, so 4 read and 4 write operations every second, which I don't consider to be a lot.. And finally, my question: Will this process ever finish? If those numbers from fseek (48404774912) represent bytes, that would be something like 45 gigabytes, with this beeing a 3 terrabyte disk, which would give me 134 days to go, if the speed stays constant, and he scans the disk like this completly and only once. Do you have some advice for me? I have most of the data on that disk elsewhere, but I've put a lot of hours into sorting and merging it to this disk, so I would prefer to getting this disk up and running again, without formatting it anew. I don't think that the hardware is damaged since the disk is only a few months and since I can't see any I/O errors in the dmesg output. UPDATE: I just looked at the strace output again (2012-11-06_2300), now it looks like this: lseek(4, 1419860611072, SEEK_SET) = 1419860611072 read(4, "3#\f\2447\335\0\22A\355\374\276j\204'\207|\217V|\23\245[\7VP\251\242\276\207\317:"..., 4096) = 4096 lseek(4, 43018145792, SEEK_SET) = 43018145792 write(4, "]\206\231\342Y\204-2I\362\242\344\6R\205\361\324\177\265\317C\334V\324\260\334\275t=\10F."..., 4096) = 4096 lseek(4, 1419860615168, SEEK_SET) = 1419860615168 read(4, "\262\305\314Y\367\37x\326\245\226\226\320N\333$s\34\204\311\222\7\315\236\336\300TK\337\264\236\211n"..., 4096) = 4096 lseek(4, 43018149888, SEEK_SET) = 43018149888 write(4, "\271\224m\311\224\25!I\376\16;\377\0\223H\25Yd\201Y\342\r\203\271\24eG<\202{\373V"..., 4096) = 4096 lseek(4, 1419860619264, SEEK_SET) = 1419860619264 read(4, ";d\360\177\n\346\253\210\222|\250\352T\335M\33\260\320\261\7g\222P\344H?t\240\20\2548\310"..., 4096) = 4096 lseek(4, 43018153984, SEEK_SET) = 43018153984 write(4, "\360\252j\317\310\251G\227\335{\214`\341\267\31Y\202\360\v\374\307oq\3063\217Z\223\313\36D\211"..., 4096) = 4096 So this number of the lseeks before the reads, like 1419860619264 are already a lot bigger, standing for 1.29 terabytes if the numbers are bytes, so it doesn't seem to be a linear progress on a big scale, maybe there are only some areas that need work, that have big gaps in between them. (times are in CET)

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• I can connect to Samba server but cannot access shares.

  - by jlego

  I'm having trouble getting samba sharing working to access shares. I have setup a stand-alone box running Fedora 16 to use as a file-sharing and web development server. It needs to be able to share files with a Windows 7 PC and a Mac running OSX Snow Leopard. I've setup Samba using the Samba configuration GUI tool on Fedora. Added users to Fedora and connected them as Samba users (which are the same as the Windows and Mac usernames and passwords). The workgroup name is the same as the Windows workgroup. Authentication is set to User. I've allowed Samba and Samba client through the firewall and set the ethernet to a trusted port in the firewall. Both the Windows and Mac machines can connect to the server and view the shares, however when trying to access the shares, Windows throws error: 0x80070035 " Windows cannot access \\SERVERNAME\ShareName." Windows user is not prompted for a username or password when accessing the server (found under "Network Places"). This also happens when connecting with the IP rather than the server name. The Mac can also connect to the server and see the shares but when choosing a share gives the error: The original item for ShareName cannot be found. When connecting via IP, the Mac user is prompted for username and password, which when authenticated gives a list of shares, however when choosing a share to connect to, the error is displayed and the user cannot access the share. Since both machines are acting similarly when trying to access the shares, I assume it is an issue with how Samba is configured. smb.conf: [global] workgroup = workgroup server string = Server log file = /var/log/samba/log.%m max log size = 50 security = user load printers = yes cups options = raw printcap name = lpstat printing = cups [homes] comment = Home Directories browseable = no writable = yes [printers] comment = All Printers path = /var/spool/samba browseable = yes printable = yes [FileServ] comment = FileShare path = /media/FileServ read only = no browseable = yes valid users = user1, user2 [webdev] comment = Web development path = /var/www/html/webdev read only = no browseable = yes valid users = user1 How do I get samba sharing working? UPDATE: I Figured it out, it was because I was sharing a second hard drive. See checked answer below. Speculation 1: Before this box I had another box with the same version of fedora installed (16) and samba working for these same computers. I started up the old machine and copied the smb.conf file from the old machine to the new one (editing the share definitions for the new shares of course) and I still get the same errors on both client machines. The only difference in environment is the hardware and the router. On the old machine the router received a dynamic public IP and assigned dynamic private IPs to each device on the network while the new machine is connected to a router that has a static public IP (still dynamic internal IPs though.) Could either one of these be affecting Samba? Speculation 2: As the directory I am trying to share is actually an entire internal disk, I have tried these things: 1.) changing the owner of the mounted disk from root to my user (which is the same username as on the Windows machine) 2.) made a share that only included one of the folders on the disk instead of the entire disk with my user again as the owner. Both tests failed giving me the same errors regarding the network address. Speculation 3: Whenever I try to connect to the share on the Windows 7 client I am prompted for my username and password. When I enter the correct credentials I get an access denied message. However I did notice that under the login box "domain: WINDOWS-PC-NAME" is listed. I believe this could very well be the problem. Speculation 4: So I've completely reinstalled Fedora and Samba now. I've created a share on the first harddrive (one fedora is installed on) and I can access that fine from Windows. However when I try to share any data on the second disk, I am receiving the same error. This I believe is the problem. I think I need to change some things in fstab or fdisk or something. Speculation 5: So in fstab I mapped the drive to automount in a folder which works correctly. I also added the samba_share_t SElinux label to the mountpoint directory which now allows me to access the shares on the Windows machine, however I cannot see any of the files in the directory on the windows machine. (They are there, I can see them in the fedora file browser locally)

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• SlimDX: Lightning problem with Direct3D9

  - by Spi1988

  I am creating a simple application to get familiar with SlimDX library. I found some code written in MDX and I'm trying to convert it to run on SlimDX. I am having some problems with the light because everything is being shown as black. The code is: public partial class DirectTest : Form { private Device device= null; private float angle = 0.0f; Light light = new Light(); public DirectTest() { InitializeComponent(); this.Size = new Size(800, 600); this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.Opaque, true); } /// <summary> /// We will initialize our graphics device here /// </summary> public void InitializeGraphics() { PresentParameters pres_params = new PresentParameters() { Windowed = true, SwapEffect = SwapEffect.Discard }; device = new Device(new Direct3D(), 0, DeviceType.Hardware, this.Handle, CreateFlags.SoftwareVertexProcessing, pres_params); } private void SetupCamera() { device.SetRenderState(RenderState.CullMode, Cull.None); device.SetTransform(TransformState.World, Matrix.RotationAxis(new Vector3(angle / ((float)Math.PI * 2.0f), angle / ((float)Math.PI * 4.0f), angle / ((float)Math.PI * 6.0f)), angle / (float)Math.PI)); angle += 0.1f; device.SetTransform(TransformState.Projection, Matrix.PerspectiveFovLH((float)Math.PI / 4, this.Width / this.Height, 1.0f, 100.0f)); device.SetTransform(TransformState.View, Matrix.LookAtLH(new Vector3(0, 0, 5.0f), new Vector3(), new Vector3(0, 1, 0))); device.SetRenderState(RenderState.Lighting, false); } protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) { device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, Color.CornflowerBlue, 1.0f, 0); SetupCamera(); CustomVertex.PositionColored[] verts = new CustomVertex.PositionColored[3]; verts[0].Position = new Vector3(0.0f, 1.0f, 1.0f); verts[0].Normal = new Vector3(0.0f, 0.0f, -1.0f); verts[0].Color = System.Drawing.Color.White.ToArgb(); verts[1].Position = new Vector3(-1.0f, -1.0f, 1.0f); verts[1].Normal = new Vector3(0.0f, 0.0f, -1.0f); verts[1].Color = System.Drawing.Color.White.ToArgb(); verts[2].Position = new Vector3(1.0f, -1.0f, 1.0f); verts[2].Normal = new Vector3(0.0f, 0.0f, -1.0f); verts[2].Color = System.Drawing.Color.White.ToArgb(); light.Type = LightType.Point; light.Position = new Vector3(); light.Diffuse = System.Drawing.Color.White; light.Attenuation0 = 0.2f; light.Range = 10000.0f; device.SetLight(0, light); device.EnableLight(0, true); device.BeginScene(); device.VertexFormat = CustomVertex.PositionColored.format; device.DrawUserPrimitives<CustomVertex.PositionColored>(PrimitiveType.TriangleList, 1, verts); device.EndScene(); device.Present(); this.Invalidate(); } } } The Vertex Format that I am using is the following [StructLayout(LayoutKind.Sequential)] public struct PositionNormalColored { public Vector3 Position; public int Color; public Vector3 Normal; public static readonly VertexFormat format = VertexFormat.Diffuse | VertexFormat.Position | VertexFormat.Normal; } Any suggestions on what the problem might be? Thanks in Advance

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• Results Delphi users who wish to use HID USB in windows

  - by Lex Dean

  Results Delphi users who wish to use HID USB in windows HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB Contain a list if keys containing vender ID and Producer ID numbers that co inside with the USB web sites data base. These numbers and the GUID held within the key gives important information to execute the HID.dll that is otherwise imposable to execute. The Control Panel/System/Hardware/Device manager/USB Serial Bus Controllers/Mass Storage Devices/details simply lists the registry data. The access to the programmer has been documented through the API32.dll with a number of procedures that accesses the registry. But that is not the problem yet it looks like the problem!!!!!!!!! The key is info about the registry and how to use it. These keys are viewed in RegEdit.exe it’s self. Some parts of the registry like the USB have been given a windows security system type of protection with a Aurthz.dll to give the USB read and right protection. Even the api32.dll. Now only Microsoft give out these details and we all know Microsoft hate Delphi. Now C users have enjoyed this access for over 10 years now. Now some will make out that you should never give out such information because some idiot may make a stupid virus (true), but the argument is also do Delphi users need to be denied USB access for another ten years!!!!!!!!!!!!. What I do not have is the skill in is assembly code. I’m seeking for some one that can trace how regedit.exe gets its access through Aurthz.dll to access the USB data. So I’m asking all who reads this:- to partition any friend they have that has this skill to get the Aurthz.dll info needed. I find communicating with USB.org they reply when they have a positive email reply but do not bother should their email be a slightly negative policy. For all simple reasoning, all that USB had to do was to have a secure key as they have done, and to update the same data into a unsecured key every time the data is changed for USB developer to access. And not bother developers access to Aurthz.dll. Authz.dll with these functions for USB:- AuthzFreeResourceManager AuthzFreeContext AuthzAccessCheck(Flags: DWORD; AuthzClientContext: AUTHZ_CLIENT_CONTEXT_HANDLE; pRequest: PAUTHZ_ACCESS_REQUEST; AuditInfo: AUTHZ_AUDIT_INFO_HANDLE; pSecurityDescriptor: PSECURITY_DESCRIPTOR; OptionalSecurityDescriptorArray: PSECURITY_DESCRIPTOR; OptionalSecurityDescriptorCount: DWORD; //OPTIONAL, Var pReply: AUTHZ_ACCESS_REPLY; pAuthzHandle: PAUTHZ_ACCESS_CHECK_RESULTS_HANDLE): BOOl; AuthzInitializeContextFromSid(Flags: DWORD; UserSid: PSID; AuthzResourceManager: AUTHZ_RESOURCE_MANAGER_HANDLE; pExpirationTime: int64; Identifier: LUID; DynamicGroupArgs: PVOID; pAuthzClientContext: PAUTHZ_CLIENT_CONTEXT_HANDLE): BOOL; AuthzInitializeResourceManager(flags: DWORD; pfnAccessCheck: PFN_AUTHZ_DYNAMIC_ACCESS_CHECK; pfnComputeDynamicGroups: PFN_AUTHZ_COMPUTE_DYNAMIC_GROUPS; pfnFreeDynamicGroups: PFN_AUTHZ_FREE_DYNAMIC_GROUPS; ResourceManagerName: PWideChar; pAuthzResourceManager: PAUTHZ_RESOURCE_MANAGER_HANDLE): BOOL; further in Authz.h on kolers.com J Lex Dean.

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• Preloading Winforms using a Stack and Hidden Form

  - by msarchet

  I am currently working on a project where we have a couple very control heavy user controls that are being used inside a MDI Controller. This is a Line of Business app and it is very data driven. The problem that we were facing was the aforementioned controls would load very very slowly, we dipped our toes into the waters of multi-threading for the control loading but that was not a solution for a plethora of reasons. Our solution to increasing the performance of the controls ended up being to 'pre-load' the forms onto a hidden window, create a stack of the existing forms, and pop off of the stack as the user requested a form. Now the current issue that I'm seeing that will arise as we push this 'fix' out to our testers, and the ultimately our users is this: Currently the 'hidden' window that contains the preloaded forms is visible in task manager, and can be shut down thus causing all of the controls to be lost. Then you have to create them on the fly losing the performance increase. Secondly, when the user uses up the stack we lose the performance increase (current solution to this is discussed below). For the first problem, is there a way to hide this window from task manager, perhaps by creating a parent form that encapsulates both the main form for the program and the hidden form? Our current solution to the second problem is to have an inactivity timer that when it fires checks the stacks for the forms, and loads a new form onto the stack if it isn't full. However this still has the potential of causing a hang in the UI while it creates the forms. A possible solutions for this would be to put 'used' forms back onto the stack, but I feel like there may be a better way. EDIT: For control design clarification From the comments I have realized there is a lack of clarity on what exactly the control is doing. Here is a detailed explanation of one of the controls. I have defined for this control loading time as the time it takes from when a user performs an action that would open a control, until the time a control is accessible to be edited. The control is for entering Prescriptions for a patient in the system, it has about 5 tabbed groups with a total of about 180 controls. The user selects to open a new Prescription control from inside the main program, this control is loaded into the MDI Child area of the Main Form (which is a DevExpress Ribbon Control). From the time the user clicks New (or loads an existing record) until the control is visible. The list of actions that happens in the program is this: The stack is checked for the existence of a control. If the control exists it is popped off of the stack. The control is rendered on screen. This is what takes 2 seconds The control then is populated with a blank object, or with existing data. The control is ready to use. The average percentage of loading time, across about 10 different machines, with different hardware the control rendering takes about 85 - 95 percent of the control loading time. Without using the stack the control takes about 2 seconds to load, with the stack it takes about .8 seconds, this second time is acceptable. I have looked at Henry's link and I had previously already implemented the applicable suggestions. Again I re-iterate my question as What is the best method to move controls to and from the stack with as little UI interruption as possible?

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• C++ custom exceptions: run time performance and passing exceptions from C++ to C

  - by skyeagle

  I am writing a custom C++ exception class (so I can pass exceptions occuring in C++ to another language via a C API). My initial plan of attack was to proceed as follows: //C++ myClass { public: myClass(); ~myClass(); void foo() // throws myException int foo(const int i, const bool b) // throws myException } * myClassPtr; // C API #ifdef __cplusplus extern "C" { #endif myClassPtr MyClass_New(); void MyClass_Destroy(myClassPtr p); void MyClass_Foo(myClassPtr p); int MyClass_FooBar(myClassPtr p, int i, bool b); #ifdef __cplusplus }; #endif I need a way to be able to pass exceptions thrown in the C++ code to the C side. The information I want to pass to the C side is the following: (a). What (b). Where (c). Simple Stack Trace (just the sequence of error messages in order they occured, no debugging info etc) I want to modify my C API, so that the API functions take a pointer to a struct ExceptionInfo, which will contain any exception info (if an exception occured) before consuming the results of the invocation. This raises two questions: Question 1 1. Implementation of each of the C++ methods exposed in the C API needs to be enclosed in a try/catch statement. The performance implications for this seem quite serious (according to this article): "It is a mistake (with high runtime cost) to use C++ exception handling for events that occur frequently, or for events that are handled near the point of detection." At the same time, I remember reading somewhere in my C++ days, that all though exception handling is expensive, it only becmes expensive when an exception actually occurs. So, which is correct?. what to do?. Is there an alternative way that I can trap errors safely and pass the resulting error info to the C API?. Or is this a minor consideration (the article after all, is quite old, and hardware have improved a bit since then). Question 2 I wuld like to modify the exception class given in that article, so that it contains a simple stack trace, and I need some help doing that. Again, in order to make the exception class 'lightweight', I think its a good idea not to include any STL classes, like string or vector (good idea/bad idea?). Which potentially leaves me with a fixed length C string (char*) which will be stack allocated. So I can maybe just keep appending messages (delimted by a unique separator [up to maximum length of buffer])... Its been a while since I did any serious C++ coding, and I will be grateful for the help. BTW, this is what I have come up with so far (I am intentionally, not deriving from std::exception because of the performance reasons mentioned in the article, and I am instead, throwing an integral exception (based on an exception enumeration): class fast_exception { public: fast_exception(int what, char const* file=0, int line=0) : what_(what), line_(line), file_(file) {/*empty*/} int what() const { return what_; } int line() const { return line_; } char const* file() const { return file_; } private: int what_; int line_; char const[MAX_BUFFER_SIZE] file_; }

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• Does anyone have database, programming language/framework suggestions for a GUI point of sale system

  - by Jason Down

  Our company has a point of sale system with many extras, such as ordering and receiving functionality, sales and order history etc. Our main issue is that the system was not designed properly from the ground up, so it takes too long to make fixes and handle requests from our customers. Also, the current technology we are using (Progress database, Progress 4GL for the language) incurs quite a bit of licensing expenses on our customers due to mutli-user license fees for database connections etc. After a lot of discussion it is looking like we will probably start over from scratch (while maintaining the current product at least for the time being). We are looking for a couple of things: Create the system with a nice GUI front end (it is currently CHUI and the application was not built in a way that allows us to redesign the front end... no layering or separation of business logic and gui...shudder). Create the system with the ability to modularize different functionality so the product doesn't have to include all features. This would keep the cost down for our current customers that want basic functionality and a lower price tag. The bells and whistles would be available for those that would want them. Use proper design patterns to make the product easy to add or change any part at any time (i.e. change the database or change the front end without needing to rewrite the application or most of it). This is a problem today because the Progress 4GL code is directly compiled against the database. Small changes in the database requires lots of code recompiling. Our new system will be Linux based, with a possibility of a client application providing functionality from one or more windows boxes. So what I'm looking for is any suggestions on which database and/or framework or programming language(s) someone might recommend for this sort of product. Anyone that has experience in this field might be able to point us in the right direction or even have some ideas of what to avoid. We have considered .NET and SQL Express (we don't need an enterprise level DB), but that would limit us to windows (as far as I know anyway). I have heard of Mono for writing .NET code in a Linux environment, but I don't know much about it yet. We've also considered a Java and MySql based implementation. To summarize we are looking to do the following: Keep licensing costs down on the technology we will use to develop the product (Oracle, yikes! MySQL, nice.) Deliver a solution that is easily maintainable and supportable. A solution that has a component capable of running on "old" hardware through a CHUI front end. (some of our customers have 40+ terminals which would be a ton of cash in order to convert over to a PC). Suggestions would be appreciated. Thanks [UPDATE] I should note that we are currently performing a total cost analysis. This question is intended to give us a couple of "educated" options to look into to include in or analysis. Anyone who could share experiences/suggestions about client/server setups would be appreciated (not just those who have experience with point of sale systems... that would just be a bonus).

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• DirectX: Render to a screen buffer without using a render target

  - by knight666

  Hello, I'm writing an open source 2D game engine, and I want to support as many devices and platforms as possible. I currently only have Windows Mobile though. I'm rendering using DirectX Mobile, with DirectDraw as a fallback path. However, I've run into a bit of trouble. It seems that while the reference driver supports createRenderTarget, many many many physical devices do not. I need some way to render to the screen without using a render target, because I render sprites using textured quads, but I also need to be able to draw individual pixels. This is how I do it right now: // save old values if (Error::Failed(m_D3DDevice->GetRenderTarget(&m_D3DOldTarget))) { ERROR_EXPLAIN("Could not retrieve backbuffer."); return false; } // clear render surface if (Error::Failed(m_D3DDevice->SetRenderTarget(m_D3DRenderSurface, NULL))) { ERROR_EXPLAIN("Could not set render target to render texture."); return false; } if (Error::Failed (m_D3DDevice->Clear( 0, NULL, // target rectangle D3DMCLEAR_TARGET, D3DMCOLOR_XRGB(0, 0, 0), // clear color 1.0f, 0 ) ) ) { ERROR_EXPLAIN("Failed to clear render texture."); return false; } D3DMLOCKED_RECT render_rect; if (Error::Failed(m_D3DRenderSurface->LockRect(&render_rect, NULL, NULL))) { ERROR_EXPLAIN("Failed to lock render surface pixels."); } else { m_D3DBackSurf->SetBuffer((Pixel*)render_rect.pBits); m_D3DRenderSurface->UnlockRect(); } // begin scene if (Error::Failed(m_D3DDevice->BeginScene())) { ERROR_EXPLAIN("Failed to start rendering."); return false; } // ===================== // example rendering // ===================== // some other stuff, but the most important part of rendering a sprite: device->SetTexture(0, m_Texture)); device->SetStreamSource(0, m_VertexBuffer, sizeof(Vertex)); device->DrawPrimitive(D3DMPT_TRIANGLELIST, 0, 2); // plotting a pixel Surface* target = (Surface*)Device::GetRenderMethod()->GetRenderTarget(); buffer = target->GetBuffer(); buffer[somepixel] = MAKECOLOR(255, 0, 0); // end scene if (Error::Failed(device->EndScene())) { ERROR_EXPLAIN("Failed to end scene."); return false; } // clear screen if (Error::Failed(device->SetRenderTarget(m_D3DOldTarget, NULL))) { ERROR_EXPLAIN("Couldn't set render target to backbuffer."); return false; } if (Error::Failed(device->GetBackBuffer ( 0, D3DMBACKBUFFER_TYPE_MONO, &m_D3DBack ) ) ) { ERROR_EXPLAIN("Couldn't retrieve backbuffer."); return false; } RECT dest = { 0, 0, Device::GetWidth(), Device::GetHeight() }; if (Error::Failed( device->StretchRect ( m_D3DRenderSurface, NULL, m_D3DBack, &dest, D3DMTEXF_NONE ) ) ) { ERROR_EXPLAIN("Failed to stretch render texture to backbuffer."); return false; } if (Error::Failed(device->Present(NULL, NULL, NULL, NULL))) { ERROR_EXPLAIN("Failed to present device."); return false; } I'm looking for a way to do the same thing (render sprites using hardware acceleration and plot pixels on a buffer) without using a render target. Thanks in advance.

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• Android: preferences not being stored automatically

  - by Vitaly

  I'm trying to use preference screen. I'm following all steps from online tutorial (once I couldn't get it working, I found other tutorials, and steps seem to be fine). I get to preferences screen, edit values, return to calling activity (via hardware return button). In DDMS perspective FileExplorer shows package_name_preferences.xml file with preferences that should be stored. It contains: <?xml version='1.0' encoding='utf-8' standalone='yes' ?> <map> <string name="false">kg</string> </map> while I expect (data line only shown). <string name="weight">kg</string> Also, if I go change only 1 preference, the same value changes, not a new row is created. I'm just tempted to write my own preference classes that would store data in files or DB, but I know that preferences should work, it just doesn't save properly my stuff. Edit Tutorials used: Main Tutorial - Was using this as a base, simplified, as I needed only 3 listPreferences so far. Another One - Used this one back when first installed android, so referred to this one for its section on preferences Code: (Screen loads, so I'm not showing Manifest) public class MyPrefs extends PreferenceActivity { @Override public void onCreate(Bundle bundle) { super.onCreate(bundle); addPreferencesFromResource(R.xml.my_prefs); } } my_prefs.xml <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"> <PreferenceCategory android:title="Value Settings"> <ListPreference android:title="Distance" android:summary="Metric (Kilometer) vs Imperial (Imperial)" android:defaultValue="km" android:key="@+id/distanceMesurement" android:entries="@array/distance" android:entryValues="@array/distance_values"/> <ListPreference android:title="Weight" android:summary="Metric (Kilogram) vs Imperial (Pound)" android:defaultValue="kg" android:key="@+id/weightMesurement" android:entries="@array/weight" android:entryValues="@array/weight_values"/> </PreferenceCategory> </PreferenceScreen> calling MyPrefs from MainScreen Intent i = new Intent(MainScreen.this, MyPrefs.class); startActivity(i); arrays.xml <resources> <string-array name="weight"> <item name="kg">Kilogram (kg)</item> <item name="lb">Pound (lb)</item> </string-array> <string-array name="weight_values"> <item name="kg">kg</item> <item name="lb">lb</item> </string-array> <string-array name="distance"> <item name="km">Kilometer (km)</item> <item name="mi">Mile (mi)</item> </string-array> <string-array name="distance_values"> <item name="km">km</item> <item name="mi">mi</item> </string-array> </resources>

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• Serial port : Read data problem, not reading complete data

  - by Anuj Mehta

  Hi I have an application where I am sending data via serial port from PC1 (Java App) and reading that data in PC2 (C++ App). The problem that I am facing is that my PC2 (C++ App) is not able to read complete data sent by PC1 i.e. from my PC1 I am sending 190 bytes but PC2 is able to read close to 140 bytes though I am trying to read in a loop. Below is code snippet of my C++ App Open the connection to serial port serialfd = open( serialPortName.c_str(), O_RDWR | O_NOCTTY | O_NDELAY); if (serialfd == -1) { /* * Could not open the port. */ TRACE << "Unable to open port: " << serialPortName << endl; } else { TRACE << "Connected to serial port: " << serialPortName << endl; fcntl(serialfd, F_SETFL, 0); } Configure the Serial Port parameters struct termios options; /* * Get the current options for the port... */ tcgetattr(serialfd, &options); /* * Set the baud rates to 9600... */ cfsetispeed(&options, B38400); cfsetospeed(&options, B38400); /* * 8N1 * Data bits - 8 * Parity - None * Stop bits - 1 */ options.c_cflag &= ~PARENB; options.c_cflag &= ~CSTOPB; options.c_cflag &= ~CSIZE; options.c_cflag |= CS8; /* * Enable hardware flow control */ options.c_cflag |= CRTSCTS; /* * Enable the receiver and set local mode... */ options.c_cflag |= (CLOCAL | CREAD); // Flush the earlier data tcflush(serialfd, TCIFLUSH); /* * Set the new options for the port... */ tcsetattr(serialfd, TCSANOW, &options); Now I am reading data const int MAXDATASIZE = 512; std::vector<char> m_vRequestBuf; char buffer[MAXDATASIZE]; int totalBytes = 0; fcntl(serialfd, F_SETFL, FNDELAY); while(1) { bytesRead = read(serialfd, &buffer, MAXDATASIZE); if(bytesRead == -1) { //Sleep for some time and read again usleep(900000); } else { totalBytes += bytesRead; //Add data read to vector for(int i =0; i < bytesRead; i++) { m_vRequestBuf.push_back(buffer[i]); } int newBytesRead = 0; //Now keep trying to read more data while(newBytesRead != -1) { //clear contents of buffer memset((void*)&buffer, 0, sizeof(char) * MAXDATASIZE); newBytesRead = read(serialfd, &buffer, MAXDATASIZE); totalBytes += newBytesRead; for(int j = 0; j < newBytesRead; j++) { m_vRequestBuf.push_back(buffer[j]); } }//inner while break; } //while

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• Architecture for Qt SIGNAL with subclass-specific, templated argument type

  - by Barry Wark

  I am developing a scientific data acquisition application using Qt. Since I'm not a deep expert in Qt, I'd like some architecture advise from the community on the following problem: The application supports several hardware acquisition interfaces but I would like to provide an common API on top of those interfaces. Each interface has a sample data type and a units for its data. So I'm representing a vector of samples from each device as a std::vector of Boost.Units quantities (i.e. std::vector<boost::units::quantity<unit,sample_type> >). I'd like to use a multi-cast style architecture, where each data source broadcasts newly received data to 1 or more interested parties. Qt's Signal/Slot mechanism is an obvious fit for this style. So, I'd like each data source to emit a signal like typedef std::vector<boost::units::quantity<unit,sample_type> > SampleVector signals: void samplesAcquired(SampleVector sampleVector); for the unit and sample_type appropriate for that device. Since tempalted QObject subclasses aren't supported by the meta-object compiler, there doesn't seem to be a way to have a (tempalted) base class for all data sources which defines the samplesAcquired Signal. In other words, the following won't work: template<T,U> //sample type and units class DataSource : public QObject { Q_OBJECT ... public: typedef std::vector<boost::units::quantity<U,T> > SampleVector signals: void samplesAcquired(SampleVector sampleVector); }; The best option I've been able to come up with is a two-layered approach: template<T,U> //sample type and units class IAcquiredSamples { public: typedef std::vector<boost::units::quantity<U,T> > SampleVector virtual shared_ptr<SampleVector> acquiredData(TimeStamp ts, unsigned long nsamples); }; class DataSource : public QObject { ... signals: void samplesAcquired(TimeStamp ts, unsigned long nsamples); }; The samplesAcquired signal now gives a timestamp and number of samples for the acquisition and clients must use the IAcquiredSamples API to retrieve those samples. Obviously data sources must subclass both DataSource and IAcquiredSamples. The disadvantage of this approach appears to be a loss of simplicity in the API... it would be much nicer if clients could get the acquired samples in the Slot connected. Being able to use Qt's queued connections would also make threading issues easier instead of having to manage them in the acquiredData method within each subclass. One other possibility, is to use a QVariant argument. This necessarily puts the onus on subclass to register their particular sample vector type with Q_REGISTER_METATYPE/qRegisterMetaType. Not really a big deal. Clients of the base class however, will have no way of knowing what type the QVariant value type is, unless a tag struct is also passed with the signal. I consider this solution at least as convoluted as the one above, as it forces clients of the abstract base class API to deal with some of the gnarlier aspects of type system. So, is there a way to achieve the templated signal parameter? Is there a better architecture than the one I've proposed?

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• Keyboard for programming

  - by exhuma

  This may seem a bit a tangential topic. It's not directly related to actual code, but is important for our line of work nevertheless. Over the years, I've switched keyboards a few times. All of them had slightly different key layouts. And I'm not talking about the language/locale layout, but the physical layout! Why not the locale layout? Well, quite frankly, that's easy to change via software. I personally have a German keyboard but have it set to the UK layout. Why? It's quite hard to find different layouts in the shops where I live. Even ordering is not always easy in the shops. So that leaves me with Internet shops. But I prefer to "test" my keyboards before buying. The most notable changes are: Mangled "Home Key Block" I've seen this first on a Logitech keyboard, but it may have originated elsewhere. Shape of the "Enter" key I've seen three different cases so far: Two lines high, wider at the top Two lines high, wider at the bottom One line high Shape of the Backspace button I've seen two types so far: One "character" wide Two "characters" wide OS Keys For Macs, you have the Option and Command buttons, for Windows you have the Windows and Context Menu buttons. Cherry even produced a Linux keyboard once (unfortunately I cannot find many details except news results). I assume a dedicated Linux keyboard would sport a Compose key and had the SysRq always labelled as well (note that some standard layouts do this already). Obviously... .. all these differences entail that some keys have to be moved around the board a lot. Which means, if you are used to one and have to work on another one, you happen to hit the wrong keys quite often. As it happens, this is much more annoying for programmers as it is for people who write texts. Mainly because the keys which are moved around are special character keys, often used in programming. Often these hardware layouts depend also indirectly on where you buy the keyboards. Honestly, I haven't seen a keyboard with a one-line "Enter" key in Germany, nor Luxembourg. I may just have missed it but that's how it looks to me at least. A survey I've seen some attempts at surveys in the style "which keyboard is best for programming". But they all - in my opinion - are not using comparable sets. So I was wondering if it was possible to concoct a survey taking the above criteria into account. But ignoring key dimensions that one would be a bit overkill I guess ;) From what I can see there are the following types of physical layout: Backspace: 2-characters wide Enter: 2-Lines, wider top Backspace: 2-characters wide Enter: 1-Line Backspace: 1-character wide Enter: 2-Lines, wider bottom Then there are the other possible permutations (home-key block, os-keys), which in total makes for quite a large list of categories. Now, I wonder... Would anyone be interested in such a survey? I personally would. Because I am looking for the perfect fit for me. If yes, then I could really use the help of anyone here to propose some models to include in the survey. Once I have some models for each category (I'd say at least 3 per category) I could go ahead and write up a survey, put it on-line and let the it collect data for a while. What do you think?

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• How do you stop scripters from slamming your website hundreds of times a second?

  - by davebug

  [update] I've accepted an answer, as lc deserves the bounty due to the well thought-out answer, but sadly, I believe we're stuck with our original worst case scenario: CAPTCHA everyone on purchase attempts of the crap. Short explanation: caching / web farms make it impossible for us to actually track hits, and any workaround (sending a non-cached web-beacon, writing to a unified table, etc.) slows the site down worse than the bots would. There is likely some pricey bit of hardware from Cisco or the like that can help at a high level, but it's hard to justify the cost if CAPTCHAing everyone is an alternative. I'll attempt to do a more full explanation in here later, as well as cleaning this up for future searchers (though others are welcome to try, as it's community wiki). I've added bounty to this question and attempted to explain why the current answers don't fit our needs. First, though, thanks to all of you who have thought about this, it's amazing to have this collective intelligence to help work through seemingly impossible problems. I'll be a little more clear than I was before: This is about the bag o' crap sales on woot.com. I'm the president of Woot Workshop, the subsidiary of Woot that does the design, writes the product descriptions, podcasts, blog posts, and moderates the forums. I work in the css/html world and am only barely familiar with the rest of the developer world. I work closely with the developers and have talked through all of the answers here (and many other ideas we've had). Usability of the site is a massive part of my job, and making the site exciting and fun is most of the rest of it. That's where the three goals below derive. CAPTCHA harms usability, and bots steal the fun and excitement out of our crap sales. To set up the scenario a little more, bots are slamming our front page tens of times a second screenscraping (and/or scanning our rss) for the Random Crap sale. The moment they see that, it triggers a second stage of the program that logs in, clicks I want One, fills out the form, and buys the crap. In current (2/6/2009) order of votes: lc: On stackoverflow and other sites that use this method, they're almost always dealing with authenticated (logged in) users, because the task being attempted requires that. On Woot, anonymous (non-logged) users can view our home page. In other words, the slamming bots can be non-authenticated (and essentially non-trackable except by IP address). So we're back to scanning for IPs, which a) is fairly useless in this age of cloud networking and spambot zombies and b) catches too many innocents given the number of businesses that come from one IP address (not to mention the issues with non-static IP ISPs and potential performance hits to trying to track this). Oh, and having people call us would be the worst possible scenario. Can we have them call you? BradC Ned Batchelder's methods look pretty cool, but they're pretty firmly designed to defeat bots built for a network of sites. Our problem is bots are built specifically to defeat our site. Some of these methods could likely work for a short time until the scripters evolved their bots to ignore the honeypot, screenscrape for nearby label names instead of form ids, and use a javascript-capable browser control. lc again "Unless, of course, the hype is part of you

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• Issue getting camera emulation to work with Tom G's HttpCamera

  - by user591524

  I am trying to use the android emulator to preview video from webcam. I have used the tom gibara sample code, minus the webbroadcaster (i am instead using VLC streaming via http). So, I have modified the SDK's "CameraPreview" app to use the HttpCamera, but the stream never appears. Debugging through doesn't give me any clues either. I wonder if anything obvious is clear to others? The preview app launches and remains black. Notes: 1) I have updated the original CameraPreview class as described here: http://www.inter-fuser.com/2009/09/live-camera-preview-in-android-emulator.html, but referencing httpCamera instead of socketcamera. 2) I updated Tom's original example to reference "Camera" type instead of deprecated "CameraDevice" type. 3) Below is my CameraPreview.java. 4) THANK YOU package com.example.android.apis.graphics; import android.app.Activity; import android.content.Context; import android.hardware.Camera; import android.os.Bundle; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.Window; import java.io.IOException; import android.graphics.Canvas; // ---------------------------------------------------------------------- public class CameraPreview extends Activity { private Preview mPreview; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Hide the window title. requestWindowFeature(Window.FEATURE_NO_TITLE); // Create our Preview view and set it as the content of our activity. mPreview = new Preview(this); setContentView(mPreview); } } // ---------------------------------------------------------------------- class Preview extends SurfaceView implements SurfaceHolder.Callback { SurfaceHolder mHolder; //Camera mCamera; HttpCamera mCamera;//changed Preview(Context context) { super(context); // Install a SurfaceHolder.Callback so we get notified when the // underlying surface is created and destroyed. mHolder = getHolder(); mHolder.addCallback(this); //mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); mHolder.setType(SurfaceHolder.SURFACE_TYPE_NORMAL);//changed } public void surfaceCreated(SurfaceHolder holder) { // The Surface has been created, acquire the camera and tell it where // to draw. //mCamera = Camera.open(); this.StartCameraPreview(holder); } public void surfaceDestroyed(SurfaceHolder holder) { // Surface will be destroyed when we return, so stop the preview. // Because the CameraDevice object is not a shared resource, it's very // important to release it when the activity is paused. //mCamera.stopPreview();//changed mCamera = null; } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // Now that the size is known, set up the camera parameters and begin // the preview. //Camera.Parameters parameters = mCamera.getParameters(); //parameters.setPreviewSize(w, h); //mCamera.setParameters(parameters); //mCamera.startPreview(); this.StartCameraPreview(holder); } private void StartCameraPreview(SurfaceHolder sh) { mCamera = new HttpCamera("10.213.74.247:443", 640, 480, true);//changed try { //mCamera.setPreviewDisplay(holder); Canvas c = sh.lockCanvas(null); mCamera.capture(c); sh.unlockCanvasAndPost(c); } catch (Exception exception) { //mCamera.release(); mCamera = null; // TODO: add more exception handling logic here } } }

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• Recompiling an old fortran 2/4\66 program that was compiled for os\2 need it to run in dos

  - by Mike Hansen

  I am helping an old scientist with some problems and have 1 program that he found and modified about 20 yrs. ago, and runs fine as a 32 bit os\2 executable but i need it to run under dos! I am not a programmer but a good hardware & software man, so I'am pretty stupid about this problem, but here go's I have downloaded 6 different compilers watcom77,silverfrost ftn95,gfortran,2 versions of g77 and f80. Watcom says it is to old of program,find older compiler,silverfrost opens it,debugs, etc. but is changing all the subroutines from "real" to "complex" and vice-vesa,and the g77's seem to install perfectly (library links and etc.) but wont even compile the test.f programs.My problem is 1; to recompile "as is" or "upgrade" the code? PROGRAM xconvlv INTEGER N,N2,M PARAMETER (N=2048,N2=2048,M=128) INTEGER i,isign REAL data(n),respns(m),resp(n),ans(n2),t3(n),DUMMY OPEN(UNIT=1, FILE='C:\QKBAS20\FDATA1.DAT') DO 1 i=1,N READ(1,*) T3(i), data(i), DUMMY continue CLOSE(UNIT-1) do 12 i=1,N respns(i)=data(i) resp(i)=respns(i) continue isign=-1 call convlv(data,N,resp,M,isign,ans) OPEN(UNIT=1,FILE='C:\QKBAS20\FDATA9.DAT') DO 14 i=1,N WRITE(1,*) T3(i), ans(i) continue END SUBROUTINE CONVLV(data,n,respns,m,isign,ans) INTEGER isign,m,n,NMAX REAL data(n),respns(n) COMPLEX ans(n) PARAMETER (NMAX=4096) * uses realft, twofft INTEGER i,no2 COMPLEX fft (NMAX) do 11 i=1, (m-1)/2 respns(n+1-i)=respns(m+1-i) continue do 12 i=(m+3)/2,n-(m-1)/2 respns(i)=0.0 continue call twofft (data,respns,fft,ans,n) no2=n/2 do 13 i=1,no2+1 if (isign.eq.1) then ans(i)=fft(i)*ans(i)/no2 else if (isign.eq.-1) then if (abs(ans(i)) .eq.0.0) pause ans(i)=fft(i)/ans(i)/no2 else pause 'no meaning for isign in convlv' endif continue ans(1)=cmplx(real (ans(1)),real (ans(no2+1))) call realft(ans,n,-1) return END SUBROUTINE realft(data,n,isign) INTEGER isign,n REAL data(n) * uses four1 INTEGER i,i1,i2,i3,i4,n2p3 REAL c1,c2,hli,hir,h2i,h2r,wis,wrs DOUBLE PRECISION theta,wi,wpi,wpr,wr,wtemp theta=3.141592653589793d0/dble(n/2) cl=0.5 if (isign.eq.1) then c2=-0.5 call four1(data,n/2,+1) else c2=0.5 theta=-theta endif (etc.,etc., etc.) SUBROUTINE twofft(data,data2,fft1,fft2,n) INTEGER n REAL data1(n,data2(n) COMPLEX fft1(n), fft2(n) * uses four1 INTEGER j,n2 COMPLEX h1,h2,c1,c2 c1=cmplx(0.5,0.0) c2=cmplx(0.0,-0.5) do 11 j=1,n fft1(j)=cmplx(data1(j),data2(j) continue call four1 (fft1,n,1) fft2(1)=cmplx(aimag(fft1(1)),0.0) fft1(1)=cmplx(real(fft1(1)),0.0) n2=n+2 do 12 j=2,n/2+1 h1=c1*(fft1(j)+conjg(fft1(n2-j))) h2=c2*(fft1(j)-conjg(fft1(n2-j))) fft1(j)=h1 fft1(n2-j)=conjg(h1) fft2(j)=h2 fft2(n2-j)=conjg(h2) continue return END SUBROUTINE four1(data,nn,isign) INTEGER isign,nn REAL data(2*nn) INTEGER i,istep,j,m,mmax,n REAL tempi,tempr DOUBLE PRECISION theta, wi,wpi,wpr,wr,wtemp n=2*nn j=1 do 11 i=1,n,2 if(j.gt.i)then tempr=data(j) tempi=data(j+1) (etc.,etc.,etc.,) continue mmax=istep goto 2 endif return END There are 4 subroutines with this that are about 3 pages of code and whould be much easier to e-mail to someone if their able to help me with this.My e-mail is [email protected] , or if someone could tell me where to get a "working" compiler that could recompile this? THANK-YOU, THANK-YOU,and THANK-YOU for any help with this! The errors Iam getting are; 1.In a call to CONVLV from another procedure,the first argument was of a type REAL(kind=1), it is now a COMPLEX(kind=1) 2.In a call to REALFT from another procedure, ... COMPLEX(kind=1) it is now a REAL(kind=1) 3.In a call to TWOFFT from...COMPLEX(kind-1) it is now a REAL(kind=1) 4.In a previous call to FOUR1, the first argument was of a type REAL(kind=1) it is now a COMPLEX(kind=1).

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• multple inner joins 3 or more crashes mysql server 5.1.30 opensolaris

  - by user331849

  when doing simple query on 4 inner joined tables, the server crashes with the output below appearing in the the mysql .err file. eg. select * from table1 inner join table2 on table1.a = table2.a and table1.b = table2.b inner join table3 on table2.a = table3.a and table2.c = table3.c inner join table4 on table3.a = table4.a and table3.d = table4.d If i remove one of the tables it executes fine. Likewise if I remove a different table, it executes fine. Though all tables have been checked anyway, this would suggest that it is not a problem specifically with one of the tables. mysql.err trace: 100503 18:13:19 - mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=1572864000 read_buffer_size=2097152 max_used_connections=11 max_threads=151 threads_connected=10 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 2155437 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. thd: 0x72febda8 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = fe07efb0 thread_stack 0x40000 Trying to get some variables. Some pointers may be invalid and cause the dump to abort... thd-query at be1021f0 = explain select * from business inner join timetable on business.id = timetable.business_id inner join timetableentry on timetable.business_id = timetableentry.business_id and timetable.kid = timetableentry.parent inner join staff on timetable.business_id = staff.business_id and timetable.staf f_person = staff.kid where business.id = '3050bb04fda41df64a9c1c149150026c' thd-thread_id=9 thd-killed=NOT_KILLED The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash. 100503 18:13:19 mysqld_safe mysqld restarted 100503 18:13:20 InnoDB: Failed to set DIRECTIO_ON on file ./ibdata1: OPEN: Inap propriate ioctl for device, continuing anyway 100503 18:13:20 InnoDB: Failed to set DIRECTIO_ON on file ./ibdata1: OPEN: Inap propriate ioctl for device, continuing anyway InnoDB: The log sequence number in ibdata files does not match InnoDB: the log sequence number in the ib_logfiles! 100503 18:13:20 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... InnoDB: Last MySQL binlog file position 0 2731, file name ./mysql-bin.000093 100503 18:13:20 InnoDB: Started; log sequence number 0 2650338426 100503 18:13:20 [Note] Recovering after a crash using mysql-bin 100503 18:13:20 [Note] Starting crash recovery... 100503 18:13:20 [Note] Crash recovery finished. This on opensolaris SunOS 5.11 snv_111b i86pc i386 i86pc Mysql 5.1.30 Here is a snippet from the my.cnf file: key_buffer = 1500M max_allowed_packet = 1M thread_stack = 256K thread_cache_size = 8 sort_buffer_size = 2M read_buffer_size = 2M read_rnd_buffer_size = 8M table_cache = 512 tmp_table_size = 400M max_heap_table_size = 64M query_cache_limit = 20M query_cache_size = 200M Is this a bug or a configuration issue?

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• Resolving a Forward Declaration Issue Involving a State Machine in C++

  - by hypersonicninja

  I've recently returned to C++ development after a hiatus, and have a question regarding implementation of the State Design Pattern. I'm using the vanilla pattern, exactly as per the GoF book. My problem is that the state machine itself is based on some hardware used as part of an embedded system - so the design is fixed and can't be changed. This results in a circular dependency between two of the states (in particular), and I'm trying to resolve this. Here's the simplified code (note that I tried to resolve this by using headers as usual but still had problems - I've omitted them in this code snippet): #include <iostream> #include <memory> using namespace std; class Context { public: friend class State; Context() { } private: State* m_state; }; class State { public: State() { } virtual void Trigger1() = 0; virtual void Trigger2() = 0; }; class LLT : public State { public: LLT() { } void Trigger1() { new DH(); } void Trigger2() { new DL(); } }; class ALL : public State { public: ALL() { } void Trigger1() { new LLT(); } void Trigger2() { new DH(); } }; // DL needs to 'know' about DH. class DL : public State { public: DL() { } void Trigger1() { new ALL(); } void Trigger2() { new DH(); } }; class HLT : public State { public: HLT() { } void Trigger1() { new DH(); } void Trigger2() { new DL(); } }; class AHL : public State { public: AHL() { } void Trigger1() { new DH(); } void Trigger2() { new HLT(); } }; // DH needs to 'know' about DL. class DH : public State { public: DH () { } void Trigger1() { new AHL(); } void Trigger2() { new DL(); } }; int main() { auto_ptr<LLT> llt (new LLT); auto_ptr<ALL> all (new ALL); auto_ptr<DL> dl (new DL); auto_ptr<HLT> hlt (new HLT); auto_ptr<AHL> ahl (new AHL); auto_ptr<DH> dh (new DH); return 0; } The problem is basically that in the State Pattern, state transitions are made by invoking the the ChangeState method in the Context class, which invokes the constructor of the next state. Because of the circular dependency, I can't invoke the constructor because it's not possible to pre-define both of the constructors of the 'problem' states. I had a look at this article, and the template method which seemed to be the ideal solution - but it doesn't compile and my knowledge of templates is a rather limited... The other idea I had is to try and introduce a Helper class to the subclassed states, via multiple inheritance, to see if it's possible to specify the base class's constructor and have a reference to the state subclasse's constructor. But I think that was rather ambitious... Finally, would a direct implmentation of the Factory Method Design Pattern be the best way to resolve the entire problem?

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• @OneToMany association joining on the wrong field

  - by april26

  I have 2 tables, devices which contains a list of devices and dev_tags, which contains a list of asset tags for these devices. The tables join on dev_serial_num, which is the primary key of neither table. The devices are unique on their ip_address field and they have a primary key identified by dev_id. The devices "age out" after 2 weeks. Therefore, the same piece of hardware can show up more than once in devices. I mention that to explain why there is a OneToMany relationship between dev_tags and devices where it seems that this should be a OneToOne relationship. So I have my 2 entities @Entity @Table(name = "dev_tags") public class DevTags implements Serializable { private Integer tagId; private String devTagId; private String devSerialNum; private List<Devices> devices; @Id @GeneratedValue @Column(name = "tag_id") public Integer getTagId() { return tagId; } public void setTagId(Integer tagId) { this.tagId = tagId; } @Column(name="dev_tag_id") public String getDevTagId() { return devTagId; } public void setDevTagId(String devTagId) { this.devTagId = devTagId; } @Column(name="dev_serial_num") public String getDevSerialNum() { return devSerialNum; } public void setDevSerialNum(String devSerialNum) { this.devSerialNum = devSerialNum; } @OneToMany(mappedBy="devSerialNum") public List<Devices> getDevices() { return devices; } public void setDevices(List<Devices> devices) { this.devices = devices; } } and this one public class Devices implements java.io.Serializable { private Integer devId; private Integer officeId; private String devSerialNum; private String devPlatform; private String devName; private OfficeView officeView; private DevTags devTag; public Devices() { } @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "dev_id", unique = true, nullable = false) public Integer getDevId() { return this.devId; } public void setDevId(Integer devId) { this.devId = devId; } @Column(name = "office_id", nullable = false, insertable=false, updatable=false) public Integer getOfficeId() { return this.officeId; } public void setOfficeId(Integer officeId) { this.officeId = officeId; } @Column(name = "dev_serial_num", nullable = false, length = 64, insertable=false, updatable=false) @NotNull @Length(max = 64) public String getDevSerialNum() { return this.devSerialNum; } public void setDevSerialNum(String devSerialNum) { this.devSerialNum = devSerialNum; } @Column(name = "dev_platform", nullable = false, length = 64) @NotNull @Length(max = 64) public String getDevPlatform() { return this.devPlatform; } public void setDevPlatform(String devPlatform) { this.devPlatform = devPlatform; } @Column(name = "dev_name") public String getDevName() { return devName; } public void setDevName(String devName) { this.devName = devName; } @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "office_id") public OfficeView getOfficeView() { return officeView; } public void setOfficeView(OfficeView officeView) { this.officeView = officeView; } @ManyToOne() @JoinColumn(name="dev_serial_num") public DevTags getDevTag() { return devTag; } public void setDevTag(DevTags devTag) { this.devTag = devTag; } } I messed around a lot with @JoinColumn(name=) and the mappedBy attribute of @OneToMany and I just cannot get this right. I finally got the darn thing to compile, but the query is still trying to join devices.dev_serial_num to dev_tags.tag_id, the @Id for this entity. Here is the transcript from the console: 13:12:16,970 INFO [STDOUT] Hibernate: select devices0_.office_id as office5_2_, devices0_.dev_id as dev1_2_, devices0_.dev_id as dev1_156_1_, devices0_.dev_name as dev2_156_1_, devices0_.dev_platform as dev3_156_1_, devices0_.dev_serial_num as dev4_156_1_, devices0_.office_id as office5_156_1_, devtags1_.tag_id as tag1_157_0_, devtags1_.comment as comment157_0_, devtags1_.dev_serial_num as dev3_157_0_, devtags1_.dev_tag_id as dev4_157_0_ from ond.devices devices0_ left outer join ond.dev_tags devtags1_ on devices0_.dev_serial_num=devtags1_.tag_id where devices0_.office_id=? 13:12:16,970 INFO [IntegerType] could not read column value from result set: dev4_156_1_; Invalid value for getInt() - 'FDO1129Y2U4' 13:12:16,970 WARN [JDBCExceptionReporter] SQL Error: 0, SQLState: S1009 13:12:16,970 ERROR [JDBCExceptionReporter] Invalid value for getInt() - 'FDO1129Y2U4' That value for getInt() 'FD01129Y2U4' is a serial number, definitely not an Int! What am I missing/misunderstanding here? Can I join 2 tables on any fields I want or does at least one have to be a primary key?

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• Help with Jquery and multiple forms on a page.

  - by Will

  I have a several forms that are output from a database on the same page. It works fine when I don't use ajax. When I use Jquery it will only work for the first form. Could anyone point me in the right direction please? Jquery..... $('.updateSubmit').live('click', function() { var id = $('.id').val(); var hardSoft = $('.hardSoft').val(); var brand = $('.brand').val(); var subCat = $('.subCat').val(); var subSubCat = $('.subSubCat').val(); var tProduct = $('.tProduct').val(); var description = $('.description').val(); var quantity = $('.quantity').val(); var price = $('.price').val(); var tCondition = $('.tCondition').val(); var featured = $('.featured').val(); var theData = 'id=' + id + '&hardSoft=' + hardSoft + '&brand=' + brand + '&subCat=' + subCat + '&subSubCat=' + subSubCat + '&tProduct=' + tProduct +'&description=' + description + '&quantity=' + quantity + '&price=' + price + '&tCondition=' + tCondition + '&featured=' + featured; $.ajax ({ type: 'POST', url: '/updateGrab.php', data: theData, success: function(aaa) { $('.'+id).append('<div class="forSuccess">'+aaa+'</div>'); } // end success }); // end ajax return false; }); // end click and my php form...... while ($row = $stmt->fetch()) { echo " <form action='http://www.wbrock.com/updateGrab.php' method='post' name='".$id."'> <input type='hidden' class='id' name='id' value='".$id."' /> Hardware/Software <input type='text' class='hardSoft' name='hardSoft' value='".$hardSoft."' /> Brand <input type='text' class='brand' name='brand' value='".$brand."' /> Sub-category <input type='text' class='subCat' name='subCat' value='".$subCat."' /> Sub-Sub-Cat <input type='text' class='subSubCat' name='subSubCat' value='".$subSubCat."' /> Product <input type='text' class='tProduct' name='tProduct' value='".$tProduct."' /> Description <input type='text' class='description' name='description' value='".$description."' /> Qty <input type='text' class='quantity' name='quantity' value='".$quantity."' /> Price <input type='text' class='price' name='price' value='".$price."' /> Cond <input type='text' class='tCondition' name='tCondition'value='".$tCondition."' /> Featured <input type='text' class='featured' name='featured' value='".$featured."' /> <input type='submit' id='".$id."' class='updateSubmit' name='updateSubmit' value='Update' /> </form> <span class='".$id."'></span> "; // end echo } // end while loop from database This is the first time I've posted here so sorry if its not in the right format. Thanks in advance for the help.

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• What language/framework (technology) to use for website (flash games portal)

  - by cripox

  Hello, I know there are a lot of similar questions on the net, but because I am a newbie in web development I didn't find the solution for my specific problem. I am planing on creating a flash games portal from scratch. It is a big chance that there will be big traffic from the beginning (millions of pageviews). I want to reduce the server costs as much as possible but in the same time to not be tide to an expensive contract as there is a chance that the project will not be as successfully as I want and in that case the money would be very little. The question is : what technology to use? I don't know any web dev technology yet so it doesn't matter what I will learn. My web dev experience is a little php 8 years ago, and from then I programmed in C++ / Java- game and mobile development. I like Java and C syntax and language very much and I tend to dislike dynamic typing or non robust scripting (like php)- but I can get along if these are the best choices. The candidates are now: - Grails (my best for now) Ruby on Rails Cake PHP Other technologies (Google App Engine, Python/Django etc...) I was considering at first using pure C and compiling the web app in the server- just to squeeze more from the servers, but soon I understand that this is overkill. Next my eyes came on Ruby - as there is a lot of buzz for it's easiness of use. Next I discovered Grails and looked at Java because it is said that it is "faster". But I don't know what this "Faster" really means on my needs, so here comes the first question: 1) What will be my biggest consumption on the server, other than bandwidth, for a lot of flash content requests? Is it memory? I heard that Java needs a lot of memory, but is faster. Is it CPU? I am planning to take some daily VPS.NET nodes at first, to see if there is a demand, and if the "spike" is permanent to move to a dedicated server (serverloft.com has some good offers), else to remain with less nodes. I was also considering developing in Google App Engine- cheap or free hosting to use at first - so I can test my assumption- and also very easy to use (no need for sys administration) but the costs became high if used more ( 3 million games played / month .. x mb/ each). And the issue with Google is that it looks me in this technology. My other concern is scalability (not only for traffic/users, but as adding functionality) My plans are to release a functional site in just 4 weeks (just the basics frontend and some quick basic backend - so I can be able to modify some things and add games manually) - but then to raise it and add more things to it. I am planning to take a little different approach than other portals so I need to write it from scratch (a script will not do). 2) Will Grails take much more resources than RoR or Php server wise? I heard that making it on Java stack will be hardware expensive and is overkill if you don't make a bank application. My application will not be very complex (I hope and i will try to) but will have a lot of traffic. I also took in account using CDN for files, but the cheapest CDN found was 5c/GB (vps.net) and the cost per gb on serverloft (http://www.serverloft.com/dedizierte-server/server-details.php?products=4) is only 1.79 cents/GB and comes with the other resources either. I am new to this domain (web). I am learning the ropes and searching on the web for ~half of year but don't have any really practical experience, so I know that I must have some naive thinking and other issues that i don't know from now, so please give me any advice you want regarding anything, not just the specific questions asked. And thank you so much for such great community!

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