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  • OpenBSD configuration: Client unable to mount via NFS using Berkeley Automounter (amd)

    - by Rilindo
    What I am trying to do is to have my openBSD client (OpenBSD 4.9) auto mount a Linux NFS file system (Scientific Linux 6.1). So far, I am not sure if it is configured correctly. To get things out of the way, I am able to mount nfs manually: # mount_nfs -T -3 192.168.15.100:/exports /mnt # ls -la /mnt total 52 drwxr-xr-x 7 root wheel 4096 Oct 4 22:42 . drwxr-xr-x 16 root wheel 512 Nov 26 16:33 .. drwxrwxr-x 5 _sndio _sndio 4096 Oct 31 21:58 centos drwxr-xr-x 15 root wheel 4096 Nov 6 09:17 home drwxr-xr-x 5 root wheel 4096 Oct 31 21:27 sl drwxr-xr-x 3 root wheel 4096 Nov 19 16:02 sles drwxr-xr-x 17 503 503 4096 Nov 10 17:37 users # So connectivity is not an issue, as far as I can tell. As per man page, the following is configured in /etc/amd/auto.home: /defaults type:=nfs;sublink:=${key};opts:=rw,soft,intr,vers=3,proto=tcp * rhost:=192.168.15.100;rfs:=/exports In turn, /etc/amd/master is configured as such: # cat /etc/amd/master /exports amd.home Upon reboot, I can it see mount, but curiously enough, instead of the hostname: amd:24490 0 0 0 100% /exports From what I understand, amd acts a little different from FreeBSD. Still, I tried to see if I it can automount. Nope: ksh: cd: /exports/users - Resource temporarily unavailable # cd /exports/192.168.15.100/host/users ksh: cd: /exports/192.168.15.100/host/users - Resource temporarily unavailable A search in google doesn't help too much - it seems that automounting NFS with OpenBSD is not something that is usually done. Other than this, information is fairly sparse. I can, of course, always mount is permanently, but I tend to be a bit anal on convention, so no for now. :) Some direction would be appreciation. (And oh, in case you are a wondering, I tried FreeBSD way of using amd and that hasn't worked out - although I wouldn't mind an explanation of the difference between how FreeBSD implements and how OpenBSD implements it) UPDATE: After re-writing the map file several times, I got as far as actually communicating with the NFS server with this configuration: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,tcp,resvport However, for some reason, it seems that amd will only default to NFS version 2 over udp: # tcpdump dst kerberos tcpdump: listening on pcn0, link-type EN10MB tcpdump: WARNING: compensating for unaligned libpcap packets 20:38:28.558385 openbsd.monzell.com.856 > kerberos.monzell.com.sunrpc: udp 100 20:38:28.559154 openbsd.monzell.com.856 > kerberos.monzell.com.892: udp 96 20:38:30.592761 openbsd.monzell.com.856 > kerberos.monzell.com.nfsd: xid 0x22000000 (NFSv2) 40 null 20:38:33.558107 arp reply openbsd.monzell.com is-at 52:54:00:52:8f:66 I tried various options of forcing it to try to mount as nfsv3 such as: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport or: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,vers=-3,proto=tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport Nothing yet still. Curious enough, OpenBSD mounts defaults to version 3, so I am not sure why it would start with version in amd. What would be the correct options to pass?

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  • OpenBSD configuration: Client unable to automount via NFS using amd

    - by Rilindo
    What I am trying to do is to have my openBSD client (OpenBSD 4.9) auto mount a Linux NFS file system (Scientific Linux 6.1). So far, I am not sure if it is configured correctly. To get things out of the way, I am able to mount nfs manually: # mount_nfs -T -3 192.168.15.100:/exports /mnt # ls -la /mnt total 52 drwxr-xr-x 7 root wheel 4096 Oct 4 22:42 . drwxr-xr-x 16 root wheel 512 Nov 26 16:33 .. drwxrwxr-x 5 _sndio _sndio 4096 Oct 31 21:58 centos drwxr-xr-x 15 root wheel 4096 Nov 6 09:17 home drwxr-xr-x 5 root wheel 4096 Oct 31 21:27 sl drwxr-xr-x 3 root wheel 4096 Nov 19 16:02 sles drwxr-xr-x 17 503 503 4096 Nov 10 17:37 users # So connectivity is not an issue, as far as I can tell. As per man page, the following is configured in /etc/amd/auto.home: /defaults type:=nfs;sublink:=${key};opts:=rw,soft,intr,vers=3,proto=tcp * rhost:=192.168.15.100;rfs:=/exports In turn, /etc/amd/master is configured as such: # cat /etc/amd/master /exports amd.home Upon reboot, I can it see mount, but curiously enough, instead of the hostname: amd:24490 0 0 0 100% /exports From what I understand, amd acts a little different from FreeBSD. Still, I tried to see if I it can automount. Nope: ksh: cd: /exports/users - Resource temporarily unavailable # cd /exports/192.168.15.100/host/users ksh: cd: /exports/192.168.15.100/host/users - Resource temporarily unavailable A search in google doesn't help too much - it seems that automounting NFS with OpenBSD is not something that is usually done. Other than this, information is fairly sparse. I can, of course, always mount is permanently, but I tend to be a bit anal on convention, so no for now. :) Some direction would be appreciation. (And oh, in case you are a wondering, I tried FreeBSD way of using amd and that hasn't worked out - although I wouldn't mind an explanation of the difference between how FreeBSD implements and how OpenBSD implements it) UPDATE: After re-writing the map file several times, I got as far as actually communicating with the NFS server with this configuration: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,tcp,resvport However, for some reason, it seems that amd will only default to NFS version 2 over udp: # tcpdump dst kerberos tcpdump: listening on pcn0, link-type EN10MB tcpdump: WARNING: compensating for unaligned libpcap packets 20:38:28.558385 openbsd.monzell.com.856 > kerberos.monzell.com.sunrpc: udp 100 20:38:28.559154 openbsd.monzell.com.856 > kerberos.monzell.com.892: udp 96 20:38:30.592761 openbsd.monzell.com.856 > kerberos.monzell.com.nfsd: xid 0x22000000 (NFSv2) 40 null 20:38:33.558107 arp reply openbsd.monzell.com is-at 52:54:00:52:8f:66 I tried various options of forcing it to try to mount as nfsv3 such as: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport or: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,vers=-3,proto=tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport Nothing yet still. Curious enough, OpenBSD mounts defaults to version 3, so I am not sure why it would start with version in amd. What would be the correct options to pass?

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  • Diagnosing packet loss / high latency in Ubuntu

    - by Sam Gammon
    We have a Linux box (Ubuntu 12.04) running Nginx (1.5.2), which acts as a reverse proxy/load balancer to some Tornado and Apache hosts. The upstream servers are physically and logically close (same DC, sometimes same-rack) and show sub-millisecond latency between them: PING appserver (10.xx.xx.112) 56(84) bytes of data. 64 bytes from appserver (10.xx.xx.112): icmp_req=1 ttl=64 time=0.180 ms 64 bytes from appserver (10.xx.xx.112): icmp_req=2 ttl=64 time=0.165 ms 64 bytes from appserver (10.xx.xx.112): icmp_req=3 ttl=64 time=0.153 ms We receive a sustained load of about 500 requests per second, and are currently seeing regular packet loss / latency spikes from the Internet, even from basic pings: sam@AM-KEEN ~> ping -c 1000 loadbalancer PING 50.xx.xx.16 (50.xx.xx.16): 56 data bytes 64 bytes from loadbalancer: icmp_seq=0 ttl=56 time=11.624 ms 64 bytes from loadbalancer: icmp_seq=1 ttl=56 time=10.494 ms ... many packets later ... Request timeout for icmp_seq 2 64 bytes from loadbalancer: icmp_seq=2 ttl=56 time=1536.516 ms 64 bytes from loadbalancer: icmp_seq=3 ttl=56 time=536.907 ms 64 bytes from loadbalancer: icmp_seq=4 ttl=56 time=9.389 ms ... many packets later ... Request timeout for icmp_seq 919 64 bytes from loadbalancer: icmp_seq=918 ttl=56 time=2932.571 ms 64 bytes from loadbalancer: icmp_seq=919 ttl=56 time=1932.174 ms 64 bytes from loadbalancer: icmp_seq=920 ttl=56 time=932.018 ms 64 bytes from loadbalancer: icmp_seq=921 ttl=56 time=6.157 ms --- 50.xx.xx.16 ping statistics --- 1000 packets transmitted, 997 packets received, 0.3% packet loss round-trip min/avg/max/stddev = 5.119/52.712/2932.571/224.629 ms The pattern is always the same: things operate fine for a while (<20ms), then a ping drops completely, then three or four high-latency pings (1000ms), then it settles down again. Traffic comes in through a bonded public interface (we will call it bond0) configured as such: bond0 Link encap:Ethernet HWaddr 00:xx:xx:xx:xx:5d inet addr:50.xx.xx.16 Bcast:50.xx.xx.31 Mask:255.255.255.224 inet6 addr: <ipv6 address> Scope:Global inet6 addr: <ipv6 address> Scope:Link UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 RX packets:527181270 errors:1 dropped:4 overruns:0 frame:1 TX packets:413335045 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:240016223540 (240.0 GB) TX bytes:104301759647 (104.3 GB) Requests are then submitted via HTTP to upstream servers on the private network (we can call it bond1), which is configured like so: bond1 Link encap:Ethernet HWaddr 00:xx:xx:xx:xx:5c inet addr:10.xx.xx.70 Bcast:10.xx.xx.127 Mask:255.255.255.192 inet6 addr: <ipv6 address> Scope:Link UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 RX packets:430293342 errors:1 dropped:2 overruns:0 frame:1 TX packets:466983986 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:77714410892 (77.7 GB) TX bytes:227349392334 (227.3 GB) Output of uname -a: Linux <hostname> 3.5.0-42-generic #65~precise1-Ubuntu SMP Wed Oct 2 20:57:18 UTC 2013 x86_64 GNU/Linux We have customized sysctl.conf in an attempt to fix the problem, with no success. Output of /etc/sysctl.conf (with irrelevant configs omitted): # net: core net.core.netdev_max_backlog = 10000 # net: ipv4 stack net.ipv4.tcp_ecn = 2 net.ipv4.tcp_sack = 1 net.ipv4.tcp_fack = 1 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 0 net.ipv4.tcp_timestamps = 1 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_no_metrics_save = 1 net.ipv4.tcp_max_syn_backlog = 10000 net.ipv4.tcp_congestion_control = cubic net.ipv4.ip_local_port_range = 8000 65535 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_synack_retries = 2 net.ipv4.tcp_thin_dupack = 1 net.ipv4.tcp_thin_linear_timeouts = 1 net.netfilter.nf_conntrack_max = 99999999 net.netfilter.nf_conntrack_tcp_timeout_established = 300 Output of dmesg -d, with non-ICMP UFW messages suppressed: [508315.349295 < 19.852453>] [UFW BLOCK] IN=bond1 OUT= MAC=<mac addresses> SRC=118.xx.xx.143 DST=50.xx.xx.16 LEN=68 TOS=0x00 PREC=0x00 TTL=51 ID=43221 PROTO=ICMP TYPE=3 CODE=1 [SRC=50.xx.xx.16 DST=118.xx.xx.143 LEN=40 TOS=0x00 PREC=0x00 TTL=249 ID=10220 DF PROTO=TCP SPT=80 DPT=53817 WINDOW=8190 RES=0x00 ACK FIN URGP=0 ] [517787.732242 < 0.443127>] Peer 190.xx.xx.131:59705/80 unexpectedly shrunk window 1155488866:1155489425 (repaired) How can I go about diagnosing the cause of this problem, on a Debian-family Linux box?

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  • Mod_Rewrite Apache ProxyPass ?

    - by Anon
    I have two websites; OLDSITE and NEWSITE. The OLDSITE has 120 IP Address that it has with it, and the NEWSITE had 5. I want to be able to separate everything from OLDSITE and NEWSITE so they are not tied together but use them on the same linux computer. My current apache setup is this: Listen 80 NameVirtualHost * <VirtualHost *> ServerName oldsite.com ServerAdmin [email protected] DocumentRoot /var/www/ <Directory /var/www/> Options Indexes FollowSymLinks MultiViews AllowOverride All Order allow,deny allow from all </Directory> RewriteEngine on RewriteCond %{HTTP_HOST} ^([^.]+)\.oldsite\.com$ RewriteCond /home/%1/ -d RewriteRule ^(.+) %{HTTP_HOST}$1 RewriteRule ^([^.]+)\.oldsite\.com/media/(.*) /home/$1/dir/media/$2 RewriteRule ^([^.]+)\.oldsite\.com/(.*) /home/$1/www/$2 </VirtualHost> <VirtualHost newsite.com> ServerName newsite.com ServerAdmin [email protected] DocumentRoot /var/newsite/ <Directory /var/newsite/> Options Indexes FollowSymLinks MultiViews AllowOverride All Order allow,deny allow from all </Directory> RewriteEngine on RewriteCond %{HTTP_HOST} ^([^.]+)\.newsite\.com$ RewriteCond /home/%1/ -d RewriteRule ^(.+) %{HTTP_HOST}$1 RewriteRule ^([^.]+)\.newsite\.com/media/(.*) /home/$1/dir/media/$2 RewriteRule ^([^.]+)\.newsite\.com/(.*) /home/$1/www/$2 </VirtualHost> <VirtualHost *> ServerName panel.oldsite.com ProxyPass / http://panel.oldsite.com:10000/ ProxyPassReverse / http://panel.oldsite.com:10000/ <Proxy *> allow from all </Proxy> </VirtualHost> <VirtualHost *> ServerName panel.newsite.com ProxyPass / http://panel.newsite.com:10000/ ProxyPassReverse / http://panel.newsite.com:10000/ <Proxy *> allow from all </Proxy> </VirtualHost> I want to be able to access anything that is newsite.com and have it go to the /var/newsite unless their is a home directory...and then if its panel.newsite.com I want it to automatically do a proxypass to panel.newsite.com:10000... With this setup, it works perfect for oldsite.com.... both the proxy and the webpages... However, having the Virtualhost set to newsite.com renders the proxypass worthless. If I change the Virtualhost for the newsite.com to a wildcard, the proxypass will work but anything thats a subdomain of newsite.com won't work. so newsite.com will work, but www.newsite.com will not load correctly. I am assuming that when everything is wildcarded, then the ServerName somewhat acts like a RewriteCond and actually just applies the stuff to that URL. It uses the Virtualhost * (oldsite.com) and lets ANYTHING.oldsite.com work, but the second virtualhost * (newsite.com) only newsite.com will work... www.newsite.com will not. If I change the order of them, the opposite is true. So apparently it doesn't like me using 2 wildcards... I tried just making the Servername *.newsite.com .......but that would be too easy. I am not sure what I can do to do what I want? Perhaps I should make the ProxyPass included in the VirtualHosts and use something like: RewriteCond %{HTTP_HOST} ^panel\.newsite\.com$ [NC] RewriteRule ^(.*)$ http://panel.newsite.com:10000/ [P] ProxyPassReverse / http://panel.newsite.com:10000/ but that doesnt seem to want to login to webmin, it loads the login page but isnt working how the ProxyPass & ProxyPassReverse does.

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  • Deterministic/Consistent Unique Masking

    - by Dinesh Rajasekharan-Oracle
    One of the key requirements while masking data in large databases or multi database environment is to consistently mask some columns, i.e. for a given input the output should always be the same. At the same time the masked output should not be predictable. Deterministic masking also eliminates the need to spend enormous amount of time spent in identifying data relationships, i.e. parent and child relationships among columns defined in the application tables. In this blog post I will explain different ways of consistently masking the data across databases using Oracle Data Masking and Subsetting The readers of post should have minimal knowledge on Oracle Enterprise Manager 12c, Application Data Modeling, Data Masking concepts. For more information on these concepts, please refer to Oracle Data Masking and Subsetting document Oracle Data Masking and Subsetting 12c provides four methods using which users can consistently yet irreversibly mask their inputs. 1. Substitute 2. SQL Expression 3. Encrypt 4. User Defined Function SUBSTITUTE The substitute masking format replaces the original value with a value from a pre-created database table. As the method uses a hash based algorithm in the back end the mappings are consistent. For example consider DEPARTMENT_ID in EMPLOYEES table is replaced with FAKE_DEPARTMENT_ID from FAKE_TABLE. The substitute masking transformation that all occurrences of DEPARTMENT_ID say ‘101’ will be replaced with ‘502’ provided same substitution table and column is used , i.e. FAKE_TABLE.FAKE_DEPARTMENT_ID. The following screen shot shows the usage of the Substitute masking format with in a masking definition: Note that the uniqueness of the masked value depends on the number of columns being used in the substitution table i.e. if the original table contains 50000 unique values, then for the masked output to be unique and deterministic the substitution column should also contain 50000 unique values without which only consistency is maintained but not uniqueness. SQL EXPRESSION SQL Expression replaces an existing value with the output of a specified SQL Expression. For example while masking an EMPLOYEES table the EMAIL_ID of an employee has to be in the format EMPLOYEE’s [email protected] while FIRST_NAME and LAST_NAME are the actual column names of the EMPLOYEES table then the corresponding SQL Expression will look like %FIRST_NAME%||’.’||%LAST_NAME%||’@COMPANY.COM’. The advantage of this technique is that if you are masking FIRST_NAME and LAST_NAME of the EMPLOYEES table than the corresponding EMAIL ID will be replaced accordingly by the masking scripts. One of the interesting aspect’s of a SQL Expressions is that you can use sub SQL expressions, which means that you can write a nested SQL and use it as SQL Expression to address a complex masking business use cases. SQL Expression can also be used to consistently replace value with hashed value using Oracle’s PL/SQL function ORA_HASH. The following SQL Expression will help in the previous example for replacing the DEPARTMENT_IDs with a hashed number ORA_HASH (%DEPARTMENT_ID%, 1000) The following screen shot shows the usage of encrypt masking format with in the masking definition: ORA_HASH takes three arguments: 1. Expression which can be of any data type except LONG, LOB, User Defined Type [nested table type is allowed]. In the above example I used the Original value as expression. 2. Number of hash buckets which can be number between 0 and 4294967295. The default value is 4294967295. You can also co-relate the number of hash buckets to a range of numbers. In the above example above the bucket value is specified as 1000, so the end result will be a hashed number in between 0 and 1000. 3. Seed, can be any number which decides the consistency, i.e. for a given seed value the output will always be same. The default seed is 0. In the above SQL Expression a seed in not specified, so it to 0. If you have to use a non default seed then the function will look like. ORA_HASH (%DEPARTMENT_ID%, 1000, 1234 The uniqueness depends on the input and the number of hash buckets used. However as ORA_HASH uses a 32 bit algorithm, considering birthday paradox or pigeonhole principle there is a 0.5 probability of collision after 232-1 unique values. ENCRYPT Encrypt masking format uses a blend of 3DES encryption algorithm, hashing, and regular expression to produce a deterministic and unique masked output. The format of the masked output corresponds to the specified regular expression. As this technique uses a key [string] to encrypt the data, the same string can be used to decrypt the data. The key also acts as seed to maintain consistent outputs for a given input. The following screen shot shows the usage of encrypt masking format with in the masking definition: Regular Expressions may look complex for the first time users but you will soon realize that it’s a simple language. There are many resources in internet, oracle documentation, oracle learning library, my oracle support on writing a Regular Expressions, out of all the following My Oracle Support document helped me to get started with Regular Expressions: Oracle SQL Support for Regular Expressions[Video](Doc ID 1369668.1) USER DEFINED FUNCTION [UDF] User Defined Function or UDF provides flexibility for the users to code their own masking logic in PL/SQL, which can be called from masking Defintion. The standard format of an UDF in Oracle Data Masking and Subsetting is: Function udf_func (rowid varchar2, column_name varchar2, original_value varchar2) returns varchar2; Where • rowid is the row identifier of the column that needs to be masked • column_name is the name of the column that needs to be masked • original_value is the column value that needs to be masked You can achieve deterministic masking by using Oracle’s built in hash functions like, ORA_HASH, DBMS_CRYPTO.MD4, DBMS_CRYPTO.MD5, DBMS_UTILITY. GET_HASH_VALUE.Please refers to the Oracle Database Documentation for more information on the Oracle Hash functions. For example the following masking UDF generate deterministic unique hexadecimal values for a given string input: CREATE OR REPLACE FUNCTION RD_DUX (rid varchar2, column_name varchar2, orig_val VARCHAR2) RETURN VARCHAR2 DETERMINISTIC PARALLEL_ENABLE IS stext varchar2 (26); no_of_characters number(2); BEGIN no_of_characters:=6; stext:=substr(RAWTOHEX(DBMS_CRYPTO.HASH(UTL_RAW.CAST_TO_RAW(text),1)),0,no_of_characters); RETURN stext; END; The uniqueness depends on the input and length of the string and number of bits used by hash algorithm. In the above function MD4 hash is used [denoted by argument 1 in the DBMS_CRYPTO.HASH function which is a 128 bit algorithm which produces 2^128-1 unique hashed values , however this is limited by the length of the input string which is 6, so only 6^6 unique values will be generated. Also do not forget about the birthday paradox/pigeonhole principle mentioned earlier in this post. An another example is to consistently replace characters or numbers preserving the length and special characters as shown below: CREATE OR REPLACE FUNCTION RD_DUS(rid varchar2,column_name varchar2,orig_val VARCHAR2) RETURN VARCHAR2 DETERMINISTIC PARALLEL_ENABLE IS stext varchar2(26); BEGIN DBMS_RANDOM.SEED(orig_val); stext:=TRANSLATE(orig_val,'ABCDEFGHILKLMNOPQRSTUVWXYZ',DBMS_RANDOM.STRING('U',26)); stext:=TRANSLATE(stext,'abcdefghijklmnopqrstuvwxyz',DBMS_RANDOM.STRING('L',26)); stext:=TRANSLATE(stext,'0123456789',to_char(DBMS_RANDOM.VALUE(1,9))); stext:=REPLACE(stext,'.','0'); RETURN stext; END; The following screen shot shows the usage of an UDF with in a masking definition: To summarize, Oracle Data Masking and Subsetting helps you to consistently mask data across databases using one or all of the methods described in this post. It saves the hassle of identifying the parent-child relationships defined in the application table. Happy Masking

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  • Cheapest way to connect 20-24 Sata II HDDs in a budget storage server?

    - by Joe Hopfgartner
    I need to assemble a high density storage server for as cheap as possible. It's been a while for me and the last systems I integrated didn't even have Sata yet... During my Research I of course stumbled about Nexsan SATA Beast, the BackBlaze storage Pods as well as some ridiculously overpriced HP Proliant or Dell storage solutions. Finally I choose Norco cases as the way to go. My eye is set on the RPC-4020, which is a 4U 19" Rackmount case with 20 Hot Swap 3.5" SATA/SAS Hdd trays (Backplanes included) and room for two 2.5" OS drives as well as a Slim Line CD-Rom. The backplanes connect with a single SATA port for each drive, so there are 20 internal SATA ports to to be connected. They also have redundant power ports which I think is quite nice. The cheapest price I have found is 290$ + 40$ shipping. In europe the cheapest unfortunately is 370€ (500$) + 40 € shipping... A nice alternative would be the RPC-4224 which has SFF-8087 Mini SAS connectors that bundle 4 SATA trays each. But it doesn't seem to be available in Europe (where i am) anywhere. So here comes my problem: What Mainboard/Controller to choose to connect them for as cheap as possible while still having nice data rates? I have to say that the server is intended as a Storage server with 1gps connectivity and the data transfer will be distributed very evenly across all drives. I also don't require any raid functionality. This is all done at application level, I just need JBOD. So for example if I go for the RPC 4020 Model I need to connect 20 Storage + 1 OS + 1 CDROM Sata ports. I searched a bit and stumbled across this very low priced controller: http://www.intel.com/products/server/raid-controllers/SASWT4I/SASWT4I-overview.htm They sell it for 115 € here and the specs say it can control up to 122 hard discs and has 4 Mini SAS connectors. So I would use 4 Mini SAS 36pin - 4 SATA 7pin cables to connect 4 SATA drives to each port and choose a Mainboard taht has 6 SATA on board (for example this one) and hurray, I can connect my 22 SATA devices for as low as about ~ 220 EUR (cpu, ram, psu, case not counted) Question: WOULD THAT WORK? And if not, why? 2nd Question: If I go for the 4220 or 4224 Model, I have internal Mini SAS connectors. Am I right in assuming that the backplane than acts as a "SAS Expander"? And can I just plug these SAS connectors into any SAS port I can find on my controller / mainboard or are there certain requirements? I know that SATA port multipliers only work with controllers that are ready for that. But isn't this expansion already implemented in the SAS standard? I am sorry that this is a very broad question, but I really spent the last week reading up and it seems to be not so clear! Especially all the controlling hardware specifications! 3rd Question: A lot of hardware specs feature "internal channels" and "internal connectors". The connecors are the physical numbers of places where I can plug a cable in. I got that. But are the "internal channels" always the maximum numbers of physical drives that can be used in the end? Or can I enhance this further by Expanders/Fanouts? 4th and last question: What do you think about the setup so far? Do you know any good alternatives? Maby I am completely going the wrong way and some DAS would be way better? Are there any comparable chassis available in europe? Please feel free to say whatever you think is relevant to the subject!

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  • DTracing TCP congestion control

    - by user12820842
    In a previous post, I showed how we can use DTrace to probe TCP receive and send window events. TCP receive and send windows are in effect both about flow-controlling how much data can be received - the receive window reflects how much data the local TCP is prepared to receive, while the send window simply reflects the size of the receive window of the peer TCP. Both then represent flow control as imposed by the receiver. However, consider that without the sender imposing flow control, and a slow link to a peer, TCP will simply fill up it's window with sent segments. Dealing with multiple TCP implementations filling their peer TCP's receive windows in this manner, busy intermediate routers may drop some of these segments, leading to timeout and retransmission, which may again lead to drops. This is termed congestion, and TCP has multiple congestion control strategies. We can see that in this example, we need to have some way of adjusting how much data we send depending on how quickly we receive acknowledgement - if we get ACKs quickly, we can safely send more segments, but if acknowledgements come slowly, we should proceed with more caution. More generally, we need to implement flow control on the send side also. Slow Start and Congestion Avoidance From RFC2581, let's examine the relevant variables: "The congestion window (cwnd) is a sender-side limit on the amount of data the sender can transmit into the network before receiving an acknowledgment (ACK). Another state variable, the slow start threshold (ssthresh), is used to determine whether the slow start or congestion avoidance algorithm is used to control data transmission" Slow start is used to probe the network's ability to handle transmission bursts both when a connection is first created and when retransmission timers fire. The latter case is important, as the fact that we have effectively lost TCP data acts as a motivator for re-probing how much data the network can handle from the sending TCP. The congestion window (cwnd) is initialized to a relatively small value, generally a low multiple of the sending maximum segment size. When slow start kicks in, we will only send that number of bytes before waiting for acknowledgement. When acknowledgements are received, the congestion window is increased in size until cwnd reaches the slow start threshold ssthresh value. For most congestion control algorithms the window increases exponentially under slow start, assuming we receive acknowledgements. We send 1 segment, receive an ACK, increase the cwnd by 1 MSS to 2*MSS, send 2 segments, receive 2 ACKs, increase the cwnd by 2*MSS to 4*MSS, send 4 segments etc. When the congestion window exceeds the slow start threshold, congestion avoidance is used instead of slow start. During congestion avoidance, the congestion window is generally updated by one MSS for each round-trip-time as opposed to each ACK, and so cwnd growth is linear instead of exponential (we may receive multiple ACKs within a single RTT). This continues until congestion is detected. If a retransmit timer fires, congestion is assumed and the ssthresh value is reset. It is reset to a fraction of the number of bytes outstanding (unacknowledged) in the network. At the same time the congestion window is reset to a single max segment size. Thus, we initiate slow start until we start receiving acknowledgements again, at which point we can eventually flip over to congestion avoidance when cwnd ssthresh. Congestion control algorithms differ most in how they handle the other indication of congestion - duplicate ACKs. A duplicate ACK is a strong indication that data has been lost, since they often come from a receiver explicitly asking for a retransmission. In some cases, a duplicate ACK may be generated at the receiver as a result of packets arriving out-of-order, so it is sensible to wait for multiple duplicate ACKs before assuming packet loss rather than out-of-order delivery. This is termed fast retransmit (i.e. retransmit without waiting for the retransmission timer to expire). Note that on Oracle Solaris 11, the congestion control method used can be customized. See here for more details. In general, 3 or more duplicate ACKs indicate packet loss and should trigger fast retransmit . It's best not to revert to slow start in this case, as the fact that the receiver knew it was missing data suggests it has received data with a higher sequence number, so we know traffic is still flowing. Falling back to slow start would be excessive therefore, so fast recovery is used instead. Observing slow start and congestion avoidance The following script counts TCP segments sent when under slow start (cwnd ssthresh). #!/usr/sbin/dtrace -s #pragma D option quiet tcp:::connect-request / start[args[1]-cs_cid] == 0/ { start[args[1]-cs_cid] = 1; } tcp:::send / start[args[1]-cs_cid] == 1 && args[3]-tcps_cwnd tcps_cwnd_ssthresh / { @c["Slow start", args[2]-ip_daddr, args[4]-tcp_dport] = count(); } tcp:::send / start[args[1]-cs_cid] == 1 && args[3]-tcps_cwnd args[3]-tcps_cwnd_ssthresh / { @c["Congestion avoidance", args[2]-ip_daddr, args[4]-tcp_dport] = count(); } As we can see the script only works on connections initiated since it is started (using the start[] associative array with the connection ID as index to set whether it's a new connection (start[cid] = 1). From there we simply differentiate send events where cwnd ssthresh (congestion avoidance). Here's the output taken when I accessed a YouTube video (where rport is 80) and from an FTP session where I put a large file onto a remote system. # dtrace -s tcp_slow_start.d ^C ALGORITHM RADDR RPORT #SEG Slow start 10.153.125.222 20 6 Slow start 138.3.237.7 80 14 Slow start 10.153.125.222 21 18 Congestion avoidance 10.153.125.222 20 1164 We see that in the case of the YouTube video, slow start was exclusively used. Most of the segments we sent in that case were likely ACKs. Compare this case - where 14 segments were sent using slow start - to the FTP case, where only 6 segments were sent before we switched to congestion avoidance for 1164 segments. In the case of the FTP session, the FTP data on port 20 was predominantly sent with congestion avoidance in operation, while the FTP session relied exclusively on slow start. For the default congestion control algorithm - "newreno" - on Solaris 11, slow start will increase the cwnd by 1 MSS for every acknowledgement received, and by 1 MSS for each RTT in congestion avoidance mode. Different pluggable congestion control algorithms operate slightly differently. For example "highspeed" will update the slow start cwnd by the number of bytes ACKed rather than the MSS. And to finish, here's a neat oneliner to visually display the distribution of congestion window values for all TCP connections to a given remote port using a quantization. In this example, only port 80 is in use and we see the majority of cwnd values for that port are in the 4096-8191 range. # dtrace -n 'tcp:::send { @q[args[4]-tcp_dport] = quantize(args[3]-tcps_cwnd); }' dtrace: description 'tcp:::send ' matched 10 probes ^C 80 value ------------- Distribution ------------- count -1 | 0 0 |@@@@@@ 5 1 | 0 2 | 0 4 | 0 8 | 0 16 | 0 32 | 0 64 | 0 128 | 0 256 | 0 512 | 0 1024 | 0 2048 |@@@@@@@@@ 8 4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@ 23 8192 | 0

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  • NUMA-aware placement of communication variables

    - by Dave
    For classic NUMA-aware programming I'm typically most concerned about simple cold, capacity and compulsory misses and whether we can satisfy the miss by locally connected memory or whether we have to pull the line from its home node over the coherent interconnect -- we'd like to minimize channel contention and conserve interconnect bandwidth. That is, for this style of programming we're quite aware of where memory is homed relative to the threads that will be accessing it. Ideally, a page is collocated on the node with the thread that's expected to most frequently access the page, as simple misses on the page can be satisfied without resorting to transferring the line over the interconnect. The default "first touch" NUMA page placement policy tends to work reasonable well in this regard. When a virtual page is first accessed, the operating system will attempt to provision and map that virtual page to a physical page allocated from the node where the accessing thread is running. It's worth noting that the node-level memory interleaving granularity is usually a multiple of the page size, so we can say that a given page P resides on some node N. That is, the memory underlying a page resides on just one node. But when thinking about accesses to heavily-written communication variables we normally consider what caches the lines underlying such variables might be resident in, and in what states. We want to minimize coherence misses and cache probe activity and interconnect traffic in general. I don't usually give much thought to the location of the home NUMA node underlying such highly shared variables. On a SPARC T5440, for instance, which consists of 4 T2+ processors connected by a central coherence hub, the home node and placement of heavily accessed communication variables has very little impact on performance. The variables are frequently accessed so likely in M-state in some cache, and the location of the home node is of little consequence because a requester can use cache-to-cache transfers to get the line. Or at least that's what I thought. Recently, though, I was exploring a simple shared memory point-to-point communication model where a client writes a request into a request mailbox and then busy-waits on a response variable. It's a simple example of delegation based on message passing. The server polls the request mailbox, and having fetched a new request value, performs some operation and then writes a reply value into the response variable. As noted above, on a T5440 performance is insensitive to the placement of the communication variables -- the request and response mailbox words. But on a Sun/Oracle X4800 I noticed that was not the case and that NUMA placement of the communication variables was actually quite important. For background an X4800 system consists of 8 Intel X7560 Xeons . Each package (socket) has 8 cores with 2 contexts per core, so the system is 8x8x2. Each package is also a NUMA node and has locally attached memory. Every package has 3 point-to-point QPI links for cache coherence, and the system is configured with a twisted ladder "mobius" topology. The cache coherence fabric is glueless -- there's not central arbiter or coherence hub. The maximum distance between any two nodes is just 2 hops over the QPI links. For any given node, 3 other nodes are 1 hop distant and the remaining 4 nodes are 2 hops distant. Using a single request (client) thread and a single response (server) thread, a benchmark harness explored all permutations of NUMA placement for the two threads and the two communication variables, measuring the average round-trip-time and throughput rate between the client and server. In this benchmark the server simply acts as a simple transponder, writing the request value plus 1 back into the reply field, so there's no particular computation phase and we're only measuring communication overheads. In addition to varying the placement of communication variables over pairs of nodes, we also explored variations where both variables were placed on one page (and thus on one node) -- either on the same cache line or different cache lines -- while varying the node where the variables reside along with the placement of the threads. The key observation was that if the client and server threads were on different nodes, then the best placement of variables was to have the request variable (written by the client and read by the server) reside on the same node as the client thread, and to place the response variable (written by the server and read by the client) on the same node as the server. That is, if you have a variable that's to be written by one thread and read by another, it should be homed with the writer thread. For our simple client-server model that means using split request and response communication variables with unidirectional message flow on a given page. This can yield up to twice the throughput of less favorable placement strategies. Our X4800 uses the QPI 1.0 protocol with source-based snooping. Briefly, when node A needs to probe a cache line it fires off snoop requests to all the nodes in the system. Those recipients then forward their response not to the original requester, but to the home node H of the cache line. H waits for and collects the responses, adjudicates and resolves conflicts and ensures memory-model ordering, and then sends a definitive reply back to the original requester A. If some node B needed to transfer the line to A, it will do so by cache-to-cache transfer and let H know about the disposition of the cache line. A needs to wait for the authoritative response from H. So if a thread on node A wants to write a value to be read by a thread on node B, the latency is dependent on the distances between A, B, and H. We observe the best performance when the written-to variable is co-homed with the writer A. That is, we want H and A to be the same node, as the writer doesn't need the home to respond over the QPI link, as the writer and the home reside on the very same node. With architecturally informed placement of communication variables we eliminate at least one QPI hop from the critical path. Newer Intel processors use the QPI 1.1 coherence protocol with home-based snooping. As noted above, under source-snooping a requester broadcasts snoop requests to all nodes. Those nodes send their response to the home node of the location, which provides memory ordering, reconciles conflicts, etc., and then posts a definitive reply to the requester. In home-based snooping the snoop probe goes directly to the home node and are not broadcast. The home node can consult snoop filters -- if present -- and send out requests to retrieve the line if necessary. The 3rd party owner of the line, if any, can respond either to the home or the original requester (or even to both) according to the protocol policies. There are myriad variations that have been implemented, and unfortunately vendor terminology doesn't always agree between vendors or with the academic taxonomy papers. The key is that home-snooping enables the use of a snoop filter to reduce interconnect traffic. And while home-snooping might have a longer critical path (latency) than source-based snooping, it also may require fewer messages and less overall bandwidth. It'll be interesting to reprise these experiments on a platform with home-based snooping. While collecting data I also noticed that there are placement concerns even in the seemingly trivial case when both threads and both variables reside on a single node. Internally, the cores on each X7560 package are connected by an internal ring. (Actually there are multiple contra-rotating rings). And the last-level on-chip cache (LLC) is partitioned in banks or slices, which with each slice being associated with a core on the ring topology. A hardware hash function associates each physical address with a specific home bank. Thus we face distance and topology concerns even for intra-package communications, although the latencies are not nearly the magnitude we see inter-package. I've not seen such communication distance artifacts on the T2+, where the cache banks are connected to the cores via a high-speed crossbar instead of a ring -- communication latencies seem more regular.

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  • Five Key Strategies in Master Data Management

    - by david.butler(at)oracle.com
    Here is a very interesting Profit Magazine article on MDM: A recent customer survey reveals the deleterious effects of data fragmentation. by Trevor Naidoo, December 2010   Across industries and geographies, IT organizations have grown in complexity, whether due to mergers and acquisitions, or decentralized systems supporting functional or departmental requirements. With systems architected over time to support unique, one-off process needs, they are becoming costly to maintain, and the Internet has only further added to the complexity. Data fragmentation has become a key inhibitor in delivering flexible, user-friendly systems. The Oracle Insight team conducted a survey assessing customers' master data management (MDM) capabilities over the past two years to get a sense of where they are in terms of their capabilities. The responses, by 27 respondents from six different industries, reveal five key areas in which customers need to improve their data management in order to get better financial results. 1. Less than 15 percent of organizations surveyed understand the sources and quality of their master data, and have a roadmap to address missing data domains. Examples of the types of master data domains referred to are customer, supplier, product, financial and site. Many organizations have multiple sources of master data with varying degrees of data quality in each source -- customer data stored in the customer relationship management system is inconsistent with customer data stored in the order management system. Imagine not knowing how many places you stored your customer information, and whether a customer's address was the most up to date in each source. In fact, more than 55 percent of the respondents in the survey manage their data quality on an ad-hoc basis. It is important for organizations to document their inventory of data sources and then profile these data sources to ensure that there is a consistent definition of key data entities throughout the organization. Some questions to ask are: How do we define a customer? What is a product? How do we define a site? The goal is to strive for one common repository for master data that acts as a cross reference for all other sources and ensures consistent, high-quality master data throughout the organization. 2. Only 18 percent of respondents have an enterprise data management strategy to ensure that data is treated as an asset to the organization. Most respondents handle data at the department or functional level and do not have an enterprise view of their master data. The sales department may track all their interactions with customers as they move through the sales cycle, the service department is tracking their interactions with the same customers independently, and the finance department also has a different perspective on the same customer. The salesperson may not be aware that the customer she is trying to sell to is experiencing issues with existing products purchased, or that the customer is behind on previous invoices. The lack of a data strategy makes it difficult for business users to turn data into information via reports. Without the key building blocks in place, it is difficult to create key linkages between customer, product, site, supplier and financial data. These linkages make it possible to understand patterns. A well-defined data management strategy is aligned to the business strategy and helps create the governance needed to ensure that data stewardship is in place and data integrity is intact. 3. Almost 60 percent of respondents have no strategy to integrate data across operational applications. Many respondents have several disparate sources of data with no strategy to keep them in sync with each other. Even though there is no clear strategy to integrate the data (see #2 above), the data needs to be synced and cross-referenced to keep the business processes running. About 55 percent of respondents said they perform this integration on an ad hoc basis, and in many cases, it is done manually with the help of Microsoft Excel spreadsheets. For example, a salesperson needs a report on global sales for a specific product, but the product has different product numbers in different countries. Typically, an analyst will pull all the data into Excel, manually create a cross reference for that product, and then aggregate the sales. The exact same procedure has to be followed if the same report is needed the following month. A well-defined consolidation strategy will ensure that a central cross-reference is maintained with updates in any one application being propagated to all the other systems, so that data is synchronized and up to date. This can be done in real time or in batch mode using integration technology. 4. Approximately 50 percent of respondents spend manual efforts cleansing and normalizing data. Information stored in various systems usually follows different standards and formats, making it difficult to match the data. A customer's address can be stored in different ways using a variety of abbreviations -- for example, "av" or "ave" for avenue. Similarly, a product's attributes can be stored in a number of different ways; for example, a size attribute can be stored in inches and can also be entered as "'' ". These types of variations make it difficult to match up data from different sources. Today, most customers rely on manual, heroic efforts to match, cleanse, and de-duplicate data -- clearly not a scalable, sustainable model. To solve this challenge, organizations need the ability to standardize data for customers, products, sites, suppliers and financial accounts; however, less than 10 percent of respondents have technology in place to automatically resolve duplicates. It is no wonder, therefore, that we get communications about products we don't own, at addresses we don't reside, and using channels (like direct mail) we don't like. An all-too-common example of a potential challenge follows: Customers end up receiving duplicate communications, which not only impacts customer satisfaction, but also incurs additional mailing costs. Cleansing, normalizing, and standardizing data will help address most of these issues. 5. Only 10 percent of respondents have the ability to share data that was mastered in a master data hub. Close to 60 percent of respondents have efforts in place that profile, standardize and cleanse data manually, and the output of these efforts are stored in spreadsheets in various parts of the organization. This valuable information is not easily shared with the rest of the organization and, more importantly, this enriched information cannot be sent back to the source systems so that the data is fixed at the source. A key benefit of a master data management strategy is not only to clean the data, but to also share the data back to the source systems as well as other systems that need the information. Aside from the source systems, another key beneficiary of this data is the business intelligence system. Having clean master data as input to business intelligence systems provides more accurate and enhanced reporting.  Characteristics of Stellar MDM When deciding on the right master data management technology, organizations should look for solutions that have four main characteristics: enterprise-grade MDM performance complete technology that can be rapidly deployed and addresses multiple business issues end-to-end MDM process management with data quality monitoring and assurance pre-built MDM business relevant applications with data stores and workflows These master data management capabilities will aid in moving closer to a best-practice maturity level, delivering tremendous efficiencies and savings as well as revenue growth opportunities as a result of better understanding your customers.  Trevor Naidoo is a senior director in Industry Strategy and Insight at Oracle. 

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  • Apache access.log interpretation

    - by Pantelis Sopasakis
    In the log file of apache (access.log) I find log entries like the following: 10.20.30.40 - - [18/Mar/2011:02:12:44 +0200] "GET /index.php HTTP/1.1" 404 505 "-" "Opera/9.80 (Windows NT 6.1; U; en) Presto/2.7.62 Version/11.01" Whose meaning is clear: The client with IP 10.20.30.40 applied a GET HTTP method on /index.php (that is to say http://mysite.org/index.php) receiving a status code 404 using Opera as client/browser. What I don't understand is entries like the following: 174.34.231.19 - - [18/Mar/2011:02:24:56 +0200] "GET http://www.siasatema.com HTTP/1.1" 200 469 "-" "Python-urllib/2.4" So here what I see is that someone (client with IP 174.34.231.19) accessed http://www.siasatema.com and got a 200 HTTP status code(?). It doesn't make sense to me... the only interpretation I can think of is that my apache server acts like proxy! Here are some other requests that don't have my site as destination... 187.35.50.61 - - [18/Mar/2011:01:28:20 +0200] "POST http://72.26.198.222:80/log/normal/ HTTP/1.0" 404 491 "-" "Octoshape-sua/1010120" 87.117.203.177 - - [18/Mar/2011:01:29:59 +0200] "CONNECT 64.12.244.203:80 HTTP/1.0" 405 556 "-" "-" 87.117.203.177 - - [18/Mar/2011:01:29:59 +0200] "open 64.12.244.203 80" 400 506 "-" "-" 87.117.203.177 - - [18/Mar/2011:01:30:04 +0200] "telnet 64.12.244.203 80" 400 506 "-" "-" 87.117.203.177 - - [18/Mar/2011:01:30:09 +0200] "64.12.244.203 80" 400 301 "-" "-" I believe that all these are related to some kind of attack or abuse of the server. Could someone explain to may what is going on and how to cope with this situation? Update 1: I disabled mod_proxy to make sure that I don't have an open proxy: # a2dismod proxy Where from I got the message: Module proxy already disabled I made sure that there is no file proxy.conf under $APACHE/mods-enabled. Finally, I set on my browser (Mozzila) my IP as a proxy and tried to access http://google.com. I was not redirected to google.com but instead my web page appeared. The same happened with trying to access http://a.b (!). So my server does not really work as a proxy since it does not forward the requests... But I think it would be better if somehow I could configure it to return a status code 403. Here is my apache configuration file: <VirtualHost *:80> ServerName mysite.org ServerAdmin webmaster@localhost DocumentRoot /var/www/ <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/> Options Indexes FollowSymLinks MultiViews AllowOverride None Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog /var/log/apache2/error.log LogLevel warn CustomLog /var/log/apache2/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> </VirtualHost> Update 2: Using a block, I restrict the use of other methods than GET and POST... <Limit POST PUT CONNECT HEAD OPTIONS DELETE PATCH PROPFIND PROPPATCH MKCOL COPY MOVE LOCK UNLOCK> Order deny,allow Deny from all </Limit> <LimitExcept GET> Order deny,allow Deny from all </LimitExcept> Now methods other that GET are forbidden (403). My only question now is whether there is some trick to boot those how try to use my server as a proxy out...

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  • We've completed the first iteration

    - by CliveT
    There are a lot of features in C# that are implemented by the compiler and not by the underlying platform. One such feature is a lambda expression. Since local variables cannot be accessed once the current method activation finishes, the compiler has to go out of its way to generate a new class which acts as a home for any variable whose lifetime needs to be extended past the activation of the procedure. Take the following example:     Random generator = new Random();     Func func = () = generator.Next(10); In this case, the compiler generates a new class called c_DisplayClass1 which is marked with the CompilerGenerated attribute. [CompilerGenerated] private sealed class c__DisplayClass1 {     // Fields     public Random generator;     // Methods     public int b__0()     {         return this.generator.Next(10);     } } Two quick comments on this: (i)    A display was the means that compilers for languages like Algol recorded the various lexical contours of the nested procedure activations on the stack. I imagine that this is what has led to the name. (ii)    It is a shame that the same attribute is used to mark all compiler generated classes as it makes it hard to figure out what they are being used for. Indeed, you could imagine optimisations that the runtime could perform if it knew that classes corresponded to certain high level concepts. We can see that the local variable generator has been turned into a field in the class, and the body of the lambda expression has been turned into a method of the new class. The code that builds the Func object simply constructs an instance of this class and initialises the fields to their initial values.     c__DisplayClass1 class2 = new c__DisplayClass1();     class2.generator = new Random();     Func func = new Func(class2.b__0); Reflector already contains code to spot this pattern of code and reproduce the form containing the lambda expression, so this is example is correctly decompiled. The use of compiler generated code is even more spectacular in the case of iterators. C# introduced the idea of a method that could automatically store its state between calls, so that it can pick up where it left off. The code can express the logical flow with yield return and yield break denoting places where the method should return a particular value and be prepared to resume.         {             yield return 1;             yield return 2;             yield return 3;         } Of course, there was already a .NET pattern for expressing the idea of returning a sequence of values with the computation proceeding lazily (in the sense that the work for the next value is executed on demand). This is expressed by the IEnumerable interface with its Current property for fetching the current value and the MoveNext method for forcing the computation of the next value. The sequence is terminated when this method returns false. The C# compiler links these two ideas together so that an IEnumerator returning method using the yield keyword causes the compiler to produce the implementation of an Iterator. Take the following piece of code.         IEnumerable GetItems()         {             yield return 1;             yield return 2;             yield return 3;         } The compiler implements this by defining a new class that implements a state machine. This has an integer state that records which yield point we should go to if we are resumed. It also has a field that records the Current value of the enumerator and a field for recording the thread. This latter value is used for optimising the creation of iterator instances. [CompilerGenerated] private sealed class d__0 : IEnumerable, IEnumerable, IEnumerator, IEnumerator, IDisposable {     // Fields     private int 1__state;     private int 2__current;     public Program 4__this;     private int l__initialThreadId; The body gets converted into the code to construct and initialize this new class. private IEnumerable GetItems() {     d__0 d__ = new d__0(-2);     d__.4__this = this;     return d__; } When the class is constructed we set the state, which was passed through as -2 and the current thread. public d__0(int 1__state) {     this.1__state = 1__state;     this.l__initialThreadId = Thread.CurrentThread.ManagedThreadId; } The state needs to be set to 0 to represent a valid enumerator and this is done in the GetEnumerator method which optimises for the usual case where the returned enumerator is only used once. IEnumerator IEnumerable.GetEnumerator() {     if ((Thread.CurrentThread.ManagedThreadId == this.l__initialThreadId)               && (this.1__state == -2))     {         this.1__state = 0;         return this;     } The state machine itself is implemented inside the MoveNext method. private bool MoveNext() {     switch (this.1__state)     {         case 0:             this.1__state = -1;             this.2__current = 1;             this.1__state = 1;             return true;         case 1:             this.1__state = -1;             this.2__current = 2;             this.1__state = 2;             return true;         case 2:             this.1__state = -1;             this.2__current = 3;             this.1__state = 3;             return true;         case 3:             this.1__state = -1;             break;     }     return false; } At each stage, the current value of the state is used to determine how far we got, and then we generate the next value which we return after recording the next state. Finally we return false from the MoveNext to signify the end of the sequence. Of course, that example was really simple. The original method body didn't have any local variables. Any local variables need to live between the calls to MoveNext and so they need to be transformed into fields in much the same way that we did in the case of the lambda expression. More complicated MoveNext methods are required to deal with resources that need to be disposed when the iterator finishes, and sometimes the compiler uses a temporary variable to hold the return value. Why all of this explanation? We've implemented the de-compilation of iterators in the current EAP version of Reflector (7). This contrasts with previous version where all you could do was look at the MoveNext method and try to figure out the control flow. There's a fair amount of things we have to do. We have to spot the use of a CompilerGenerated class which implements the Enumerator pattern. We need to go to the class and figure out the fields corresponding to the local variables. We then need to go to the MoveNext method and try to break it into the various possible states and spot the state transitions. We can then take these pieces and put them back together into an object model that uses yield return to show the transition points. After that Reflector can carry on optimising using its usual optimisations. The pattern matching is currently a little too sensitive to changes in the code generation, and we only do a limited analysis of the MoveNext method to determine use of the compiler generated fields. In some ways, it is a pity that iterators are compiled away and there is no metadata that reflects the original intent. Without it, we are always going to dependent on our knowledge of the compiler's implementation. For example, we have noticed that the Async CTP changes the way that iterators are code generated, so we'll have to do some more work to support that. However, with that warning in place, we seem to do a reasonable job of decompiling the iterators that are built into the framework. Hopefully, the EAP will give us a chance to find examples where we don't spot the pattern correctly or regenerate the wrong code, and we can improve things. Please give it a go, and report any problems.

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  • Cancelling Route Navigation in AngularJS Controllers

    - by dwahlin
    If you’re new to AngularJS check out my AngularJS in 60-ish Minutes video tutorial or download the free eBook. Also check out The AngularJS Magazine for up-to-date information on using AngularJS to build Single Page Applications (SPAs). Routing provides a nice way to associate views with controllers in AngularJS using a minimal amount of code. While a user is normally able to navigate directly to a specific route, there may be times when a user triggers a route change before they’ve finalized an important action such as saving data. In these types of situations you may want to cancel the route navigation and ask the user if they’d like to finish what they were doing so that their data isn’t lost. In this post I’ll talk about a technique that can be used to accomplish this type of routing task.   The $locationChangeStart Event When route navigation occurs in an AngularJS application a few events are raised. One is named $locationChangeStart and the other is named $routeChangeStart (there are other events as well). At the current time (version 1.2) the $routeChangeStart doesn’t provide a way to cancel route navigation, however, the $locationChangeStart event can be used to cancel navigation. If you dig into the AngularJS core script you’ll find the following code that shows how the $locationChangeStart event is raised as the $browser object’s onUrlChange() function is invoked:   $browser.onUrlChange(function (newUrl) { if ($location.absUrl() != newUrl) { if ($rootScope.$broadcast('$locationChangeStart', newUrl, $location.absUrl()).defaultPrevented) { $browser.url($location.absUrl()); return; } $rootScope.$evalAsync(function () { var oldUrl = $location.absUrl(); $location.$$parse(newUrl); afterLocationChange(oldUrl); }); if (!$rootScope.$$phase) $rootScope.$digest(); } }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The key part of the code is the call to $broadcast. This call broadcasts the $locationChangeStart event to all child scopes so that they can be notified before a location change is made. To handle the $locationChangeStart event you can use the $rootScope.on() function. For this example I’ve added a call to $on() into a function that is called immediately after the controller is invoked:   function init() { //initialize data here.. //Make sure they're warned if they made a change but didn't save it //Call to $on returns a "deregistration" function that can be called to //remove the listener (see routeChange() for an example of using it) onRouteChangeOff = $rootScope.$on('$locationChangeStart', routeChange); } This code listens for the $locationChangeStart event and calls routeChange() when it occurs. The value returned from calling $on is a “deregistration” function that can be called to detach from the event. In this case the deregistration function is named onRouteChangeOff (it’s accessible throughout the controller). You’ll see how the onRouteChangeOff function is used in just a moment.   Cancelling Route Navigation The routeChange() callback triggered by the $locationChangeStart event displays a modal dialog similar to the following to prompt the user:     Here’s the code for routeChange(): function routeChange(event, newUrl) { //Navigate to newUrl if the form isn't dirty if (!$scope.editForm.$dirty) return; var modalOptions = { closeButtonText: 'Cancel', actionButtonText: 'Ignore Changes', headerText: 'Unsaved Changes', bodyText: 'You have unsaved changes. Leave the page?' }; modalService.showModal({}, modalOptions).then(function (result) { if (result === 'ok') { onRouteChangeOff(); //Stop listening for location changes $location.path(newUrl); //Go to page they're interested in } }); //prevent navigation by default since we'll handle it //once the user selects a dialog option event.preventDefault(); return; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Looking at the parameters of routeChange() you can see that it accepts an event object and the new route that the user is trying to navigate to. The event object is used to prevent navigation since we need to prompt the user before leaving the current view. Notice the call to event.preventDefault() at the end of the function. The modal dialog is shown by calling modalService.showModal() (see my previous post for more information about the custom modalService that acts as a wrapper around Angular UI Bootstrap’s $modal service). If the user selects “Ignore Changes” then their changes will be discarded and the application will navigate to the route they intended to go to originally. This is done by first detaching from the $locationChangeStart event by calling onRouteChangeOff() (recall that this is the function returned from the call to $on()) so that we don’t get stuck in a never ending cycle where the dialog continues to display when they click the “Ignore Changes” button. A call is then made to $location.path(newUrl) to handle navigating to the target view. If the user cancels the operation they’ll stay on the current view. Conclusion The key to canceling routes is understanding how to work with the $locationChangeStart event and cancelling it so that route navigation doesn’t occur. I’m hoping that in the future the same type of task can be done using the $routeChangeStart event but for now this code gets the job done. You can see this code in action in the Customer Manager application available on Github (specifically the customerEdit view). Learn more about the application here.

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  • Introduction to Human Workflow 11g

    - by agiovannetti
    Human Workflow is a component of SOA Suite just like BPEL, Mediator, Business Rules, etc. The Human Workflow component allows you to incorporate human intervention in a business process. You can use Human Workflow to create a business process that requires a manager to approve purchase orders greater than $10,000; or a business process that handles article reviews in which a group of reviewers need to vote/approve an article before it gets published. Human Workflow can handle the task assignment and routing as well as the generation of notifications to the participants. There are three common patterns or usages of Human Workflow: 1) Approval Scenarios: manage documents and other transactional data through approval chains . For example: approve expense report, vacation approval, hiring approval, etc. 2) Reviews by multiple users or groups: group collaboration and review of documents or proposals. For example, processing a sales quote which is subject to review by multiple people. 3) Case Management: workflows around work management or case management. For example, processing a service request. This could be routed to various people who all need to modify the task. It may also incorporate ad hoc routing which is unknown at design time. SOA 11g Human Workflow includes the following features: Assignment and routing of tasks to the correct users or groups. Deadlines, escalations, notifications, and other features required for ensuring the timely performance of a task. Presentation of tasks to end users through a variety of mechanisms, including a Worklist application. Organization, filtering, prioritization and other features required for end users to productively perform their tasks. Reports, reassignments, load balancing and other features required by supervisors and business owners to manage the performance of tasks. Human Workflow Architecture The Human Workflow component is divided into 3 modules: the service interface, the task definition and the client interface module. The Service Interface handles the interaction with BPEL and other components. The Client Interface handles the presentation of task data through clients like the Worklist application, portals and notification channels. The task definition module is in charge of managing the lifecycle of a task. Who should get the task assigned? What should happen next with the task? When must the task be completed? Should the task be escalated?, etc Stages and Participants When you create a Human Task you need to specify how the task is assigned and routed. The first step is to define the stages and participants. A stage is just a logical group. A participant can be a user, a group of users or an application role. The participants indicate the type of assignment and routing that will be performed. Stages can be sequential or in parallel. You can combine them to create any usage you require. See diagram below: Assignment and Routing There are different ways a task can be assigned and routed: Single Approver: task is assigned to a single user, group or role. For example, a vacation request is assigned to a manager. If the manager approves or rejects the request, the employee is notified with the decision. If the task is assigned to a group then once one of managers acts on it, the task is completed. Parallel : task is assigned to a set of people that must work in parallel. This is commonly used for voting. For example, a task gets approved once 50% of the participants approve it. You can also set it up to be a unanimous vote. Serial : participants must work in sequence. The most common scenario for this is management chain escalation. FYI (For Your Information) : task is assigned to participants who can view it, add comments and attachments, but can not modify or complete the task. Task Actions The following is the list of actions that can be performed on a task: Claim : if a task is assigned to a group or multiple users, then the task must be claimed first to be able to act on it. Escalate : if the participant is not able to complete a task, he/she can escalate it. The task is reassigned to his/her manager (up one level in a hierarchy). Pushback : the task is sent back to the previous assignee. Reassign :if the participant is a manager, he/she can delegate a task to his/her reports. Release : if a task is assigned to a group or multiple users, it can be released if the user who claimed the task cannot complete the task. Any of the other assignees can claim and complete the task. Request Information and Submit Information : use when the participant needs to supply more information or to request more information from the task creator or any of the previous assignees. Suspend and Resume :if a task is not relevant, it can be suspended. A suspension is indefinite. It does not expire until Resume is used to resume working on the task. Withdraw : if the creator of a task does not want to continue with it, for example, he wants to cancel a vacation request, he can withdraw the task. The business process determines what happens next. Renew : if a task is about to expire, the participant can renew it. The task expiration date is extended one week. Notifications Human Workflow provides a mechanism for sending notifications to participants to alert them of changes on a task. Notifications can be sent via email, telephone voice message, instant messaging (IM) or short message service (SMS). Notifications can be sent when the task status changes to any of the following: Assigned/renewed/delegated/reassigned/escalated Completed Error Expired Request Info Resume Suspended Added/Updated comments and/or attachments Updated Outcome Withdraw Other Actions (e.g. acquiring a task) Here is an example of an email notification: Worklist Application Oracle BPM Worklist application is the default user interface included in SOA Suite. It allows users to access and act on tasks that have been assigned to them. For example, from the Worklist application, a loan agent can review loan applications or a manager can approve employee vacation requests. Through the Worklist Application users can: Perform authorized actions on tasks, acquire and check out shared tasks, define personal to-do tasks and define subtasks. Filter tasks view based on various criteria. Work with standard work queues, such as high priority tasks, tasks due soon and so on. Work queues allow users to create a custom view to group a subset of tasks in the worklist, for example, high priority tasks, tasks due in 24 hours, expense approval tasks and more. Define custom work queues. Gain proxy access to part of another user's tasks. Define custom vacation rules and delegation rules. Enable group owners to define task dispatching rules for shared tasks. Collect a complete workflow history and audit trail. Use digital signatures for tasks. Run reports like Unattended tasks, Tasks productivity, etc. Here is a screenshoot of what the Worklist Application looks like. On the right hand side you can see the tasks that have been assigned to the user and the task's detail. References Introduction to SOA Suite 11g Human Workflow Webcast Note 1452937.2 Human Workflow Information Center Using the Human Workflow Service Component 11.1.1.6 Human Workflow Samples Human Workflow APIs Java Docs

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  • Problems with XP, Office, and PC in general - any ideas?

    - by molecule
    Hi all This may not make a whole lot of sense so pls bear with me... I am about to perform a routine check on one of my user's PC. Some background - the PC has a Xeon processor and 4Gb of RAM and running XP SP3 He has 2xHDD and pagefile is hosted on the secondary HDD (D:) and min/max values are set to 4096. NO pagefile on C: This user has 6 monitors so he has an NVIDIA Quadro NVS440 hosting 4xmonitors and an NVIDIA Quadro NVS290 hosting 2xmonitors. There is a video card driver from NVIDIA which is compatible with both NVS440 and NVS290 and he is on the latest version of that driver. (Note: Make of video cards are different - one is from leadtek and the other from Nvidia) He is a heavy Bloomberg, Outlook, Word, and Excel user and runs two Citrix applications. Other apps are FoxIt PDF and IE. Problems - Outlook and Excel frequently crashes - I am going to perform an Outlook and Excel repair and also check/remove unnecessary addins - will he lose any customizations if I repaired and chose "Restore my shortcuts while repairing" and do not select "Discard my customized settings and restore default settings". Does repair really repair anything? FYI - It stopped crashing ever since i moved a large spreadsheet he has open to his local HDD instead of over the network. This spreadsheet "refreshes" constantly as it is pulling live data to update cells and I suspect it was auto-saving so frequently that it caused crashes if saving over the network. At times, his right click completely fails to respond. His left click works fine but he can't right click on anything in any Window and even on the desktop. Sometimes, he needs to start to close certain applications such as Adobe and the right click will start functioning again. I removed Adobe and installed FoxIt as I figured it was a resource issue but I do not think so as he does have sufficient resources when the problem is happening. Sometimes he can't bring task manager up until he kills certain apps. Definitely sounds like a resource issue but I am not confident that is the root cause. Also not sure if this is related to one of the apps installed but his Start bar flickers (does not completely disappear) intermittently from time to time. The taskbar icons which are hidden appear and then get hidden again as if it was having "fits". I have performed reg scans, malware scans etc but problems do not go away. I am planning to perform sfc /scannow and office repair but would like to know if anyone has any other suggestions. What about setting a "small" pagefile on C:. I have heard that this is recommended and may be the reason why a minidmp file was not generated when he encountered a blue screen. Also, any feedback on his video cards? Do you think different models would cause problems? The drivers seem to work but he only has 2.5Gb out of 4Gb available RAM as I believe the video card chomped up a portion of this. I have recommended creating a new profile for him but due to the amount of customisations he has and the amount of time and effort it will take to get him up and running again, he prefers to bear with the problem than to go down that path. However, at least once a week, his PC acts up and I can't think of any other tools or techniques to rectify his problems. I guess we are at a stage where we just want to "stabilize" things so he won't encounter issues that frequently. Any feedback is very much appreciated.

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  • I am starting to think that Prevx.com isnt a legit site...but heres my long-winded question

    - by cop1152
    I apologize in advance for the long-winded post. I posted it all because I believe its informative and may be useful. Also, I posted my question at the end. Moments ago I was RDC to a file server in my home (from inside my home). I had opened Firefox and Googled for a manufacturers website. Immediately after clicking the link, Firefox abruptly closed. This seemed odd to me to so I checked the running processes and discovered d.exe, e.exe, and f.exe running. I Googled these processes on a different machine and found them belonging to a key-logger/screen-capturer/trojan called defender.exe, which according to the Prevx lives in c:\documents and settings\user\local settings\temp. (Prevx link http://www.prevx.com/filenames/147352809685142526-X1/DEFENDER32.EXE.html) Simultaneously, an obviously-spoofed Windows Firewall popup appeared on the server asking me to click ‘yes’ to update Windows Firewall. At this time I ended all rogue processes, emptied the temp folder, removed defender.exe from startup, and checked my registry and a few other locations. Before deleting Defender.exe I noted that it was created moments ago, just before Firefox crashed. I believe that I was ‘almost’ infected with this malware. I believe that it needed me to click the phony popup in order to complete infection because it wasn’t allowed to execute processes from the temp folder. After cleaning the machine, I restarted it and have been monitoring it for over an hour. I am debating on whether or not to restore the Windows partition (a separate physical drive from the data) or to just watch it for awhle. I should mention that, because of the specs on this machine, I do not run antivirus software, but I know it well and inspect it regularly. It is a very old Compaq with a 400mhz processer and 512mb of ram. I have a static IP and the server is in the DMZ running an FTP client and some HTTP server software. All files transferred to and stored on this machine are scanned for malware before transferring. Usually the machine only runs 19 processes and performs pretty well for its intended purpose. I posted the story so that you could be aware of a possible new piece of malware and how it acts, but I also have a question or two. First, over the last few months I have noticed that PREVX is listed at the top of most of my Google searches when researching malware, especially for new or obscure malware…and they always want you to purchase something. I don’t think they are one of the top AV companies, so it seems odd that they are always the top Google result. Does anyone have any experience with any of their products? Also, what sites do you rely on for malware researching? Recently, I have found it difficult to find good info because of HijackThis-logs and other deadend info cluttering up my searches. And lastly, besides antivirus, third-party firewall, etc, what settings would you use to lock down a machine to make it more secure in instances where a stubborn admin like myself refuses to run AV? Thanks.

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  • Network config / gear question

    - by mcgee1234
    I have been tasked with setting up a fairly straightforward rack in a data center (we do not even need a whole rack, but this is the smallest allotment available). In a nutshell, 4 to 6 servers need to be able to reach 2 (maybe 3) vendors. The servers needs to be reachable over the internet. A little more detail - the networks the servers need to reach are inside of the data center, and are "trusted". Connections to these networks will be achieved through intra data center cross connects. It is kind of like a manufacturing line where we receive data from one vendor (burst-able up to 200 Mbits), churn through it on the servers, and then send out data to another vendor (bursts up to 20 Mbits). This series of events is very latency sensitive, so much so that it is common practice not to use NAT or a firewall on these segments (or so I hear). To reach the servers over the internet, I plan to use a site to site VPN. (This part is only relevant as far as hardware selection goes). I have 2 configurations in mind: Cisco 2911 (2921) (with the additional wan ports module) and a layer 2 switch - in this scenario, I would use the router also for VPN. Cisco 3560 layer 3 switch to interconnect the networks inside of the data center and an ASA 5510 (which is total overkill, but the 5505 is not rack mountable) as a firewall for the Wan side (internet) and VPN. I envision the setup to be as follows: Internet - ASA - 3560 Vendors - 3560 - Servers The general idea is that the ASA acts as a firewall and VPN device and the 3560 does all the heavy lifting. The first is a fairly traditional setup but my concern is performance. The second is somewhat unorthodox in that the vendors are directly connected to the layer 3 switch without passing through a firewall. Based on my understanding however, a layer 3 switch will perform substantially better as it will do hardware (ASIC) vs. software switching. (Note that number 2 is a little over the budget, but not unworkable (double negative, ugh)) Since this is my first time dealing with a data center, I am not sure what the IP space is going to look like. I suspect I will retain a block(s) of public IPs, vlan them to individual interfaces for the vendor connections and the servers (which will not reachable from the wan side of course) and setup routing on the switch. So here are my questionss: Is there a substantial performance difference between 1 and 2, i.e. hardware based switching on a layer 3 vs a software base on the 2911? I have trolled the internet and found a lot of Cisco literature, but nothing that I could really use to get a good handle. The vendors we connect to are secure and trusted (famous last words) and as I understand it, it is common practice not to NAT or firewall these connections (because of the aforementioned latency sensitivity). But what what kind of latency are we really talking about if I push the data through a router (or even ASA for that matter)? For our purposes, 5 ms will not kill us, 20 or 30 can be very costly. Others measure in microseconds, but they are out of our league. Is there any issues with using public IPs on a layer 3 switch? I am certainly not married to either of these configs, and I am totally open to any ideas. My knowledge (and I use the term loosely) is largely from books so I welcome any advice / insight. Thanks in advance.

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  • "dig +trace fqdn" and "dig fqdn" do not give the same result on a LAN with windows DNS server, why?

    - by Sulliwane
    in my company LAN I have a Ubuntu 14.04 server running in Virtualbox (as guest) on a Windows 7 (the host) with network interface bridged (so the Ubuntu server belongs to the LAN, with its ip: 192.168.1.85). I have a website on this server: mywebsite.com The gateway for the LAN to the internet is 192.168.1.1 (Cisco 1841)--188.188.188.254 as public IP. There is a Windows 2008 server that acts as DNS server and DHCP server on the LAN. I added a Forward zone "mywebsite.com" with A record - 192.168.1.85. Outside the LAN, mywebsite.com has public Dns records that point on the Cisco 1841 public IP (188.188.188.254) Now when I ping mywebsite.com from the lan, I quickly get 192.168.1.85. But when I'm connecting through the browser on the clients, it's not always fast. So I'm wondering: Are my requests really/directly resolved and forwarded to 192.168.1.85, OR are they sent out of the LAN, and then forwarded back to the CISCO public 188.188.188.254:80 and NAT to the Ubuntu server before being served ??? To try to answer this question, I looked for tracking the DNS request from my linux client on the LAN: v@v-ss9:~$ dig mywebsite.com ; <<>> DiG 9.9.5-3-Ubuntu <<>> mywebsite.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24850 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4000 ;; QUESTION SECTION: ;mywebsite.com. IN A ;; ANSWER SECTION: mywebsite.com. 3600 IN A 192.168.1.85 ;; Query time: 1 msec ;; SERVER: 127.0.1.1#53(127.0.1.1) ;; WHEN: Fri Aug 22 09:50:16 CST 2014 ;; MSG SIZE rcvd: 66 This answer looks right: 192.168.1.85. But then look at this: v@v-ss9:~$ dig +trace mywebsite.com ; <<>> DiG 9.9.5-3-Ubuntu <<>> +trace mywebsite.com ;; global options: +cmd . 12955 IN NS h.gtld-servers.net. . 12955 IN NS g.gtld-servers.net. . 12955 IN NS m.gtld-servers.net. . 12955 IN NS i.gtld-servers.net. . 12955 IN NS l.gtld-servers.net. . 12955 IN NS k.gtld-servers.net. . 12955 IN NS j.gtld-servers.net. . 12955 IN NS d.gtld-servers.net. . 12955 IN NS b.gtld-servers.net. . 12955 IN NS c.gtld-servers.net. . 12955 IN NS a.gtld-servers.net. . 12955 IN NS e.gtld-servers.net. . 12955 IN NS f.gtld-servers.net. ;; Received 516 bytes from 127.0.1.1#53(127.0.1.1) in 18 ms mywebsite.com. 172800 IN NS ns3.rmi.fr. mywebsite.com. 172800 IN NS ns4.rmi.fr. CK0POJMG874LJREF7EFN8430QVIT8BSM.com. 86400 IN NSEC3 1 1 0 - CK0QFMDQRCSRU0651QLVA1JQB21IF7UR NS SOA RRSIG DNSKEY NSEC3PARAM CK0POJMG874LJREF7EFN8430QVIT8BSM.com. 86400 IN RRSIG NSEC3 8 2 86400 20140825045016 20140818034016 6122 com. Imq8K9xlvFXlB4IjUkdxOc5YHoTEhqSQUlRSJ9QCIhd9wzGpWJ54AfVf WJ0SUKThalpzqS0cXdLGtNmuYgqLfwUMjpUlT4c+zJyx7I4QMPLImQZh Ov0xy3mUr7dLlymAJYGs9dLI2IaheLvpKTBwaV1gAvo8QEkU8VRiJ7gW 9dk= U0PIA23FHMVPTKSDHC9PJ1BEA9SIB65R.com. 86400 IN NSEC3 1 1 0 - U0PL33R61V6TCCPBS1171PROP57ASRD9 NS DS RRSIG U0PIA23FHMVPTKSDHC9PJ1BEA9SIB65R.com. 86400 IN RRSIG NSEC3 8 2 86400 20140825043502 20140818032502 6122 com. qsC5sJbwklao+OedCHpcYo56aQaY0N+7peKmPu8szvjAQoJFRWyuDfAh Nw/gvHXEMzG7tYLriQGVfsiK8GZdPXyG4Ghe1MNN4jOZnSahkT5LjlqL 5QyGC0QiClRMPDAYjUOFGQDkjOJcJYvTNkEyXC2BEpfLI5SwCbYqwqg3 RkE= ;; Received 585 bytes from 192.41.162.30#53(l.gtld-servers.net) in 297 ms mywebsite.com. 86400 IN A 188.188.188.254 mywebsite.com. 86400 IN NS ns3.rmi.fr. mywebsite.com. 86400 IN NS ns4.rmi.fr. ;; Received 204 bytes from 212.51.161.18#53(ns3.rmi.fr) in 310 ms Here I get my CISCO public IP 188.188.188.254!!! Is it normal? How to know if my browser (from the LAN) is really directly communicating with 192.168.1.85 when using mywebsite.com? Thank you for your help.

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  • Unicast traffic between hosts on a switch leaving the switch by its uplink. Why?

    - by Rich Lafferty
    I have a weird thing happening on our network at my office which I can't quite get my head around. In particular I can't tell if it's a problem with a switch, or a problem with configuration. We have a Cisco SG300-52 switch (sw01) in the top of a rack in our server room, connected to another SG300-28 that acts as our core switch (core01). Both run layer 2 only, our firewalls do routing between VLANs. They have a dozen or so VLANs between them. Gi1 on sw01 is a trunk port connected to gi1 on core01. (Disclosure: There are other switches in our environment but I'm pretty sure I've isolated the problem down to these two. Happy to provide more info if necessary.) The behaviour I'm seeing is limited to one VLAN, vlan 12 -- or, at least, it's not happening on the other ones I checked (It's hard to guarantee the absence of packets), and it is: sw01 is forwarding, to core01, traffic which is between two hosts which are both plugged into sw01. (I noticed this because the IDS in our firewall gave a false positive on traffic which should not reach the firewall.) We noticed this mostly between our two dhcp/dns servers, net01 (10.12.0.10) and net02 (10.12.0.11). net01 is physical hardware and net02 is on a VMware ESX server. net01 is connected to gi44 on sw01 and net02's ESX server to gi11. [net01]----gi44-[sw01]-gi1----gi1-[core01] [net02]----gi11/ Let's see some interfaces! Remember, vlan 12 is the problem vlan. Of the others I explicitly verified that vlan 27 was not affected. Here's the two hosts' ports: esx01 contains net02. sw01#sh run int gi11 interface gigabitethernet11 description esx01 lldp med disable switchport trunk allowed vlan add 5-7,11-13,100 switchport trunk native vlan 27 ! sw01#sh run int gi44 interface gigabitethernet44 description net01-1 lldp med disable switchport mode access switchport access vlan 12 ! Here's the trunk on sw01. sw01#sh run int gi1 interface gigabitethernet1 description "trunk to core01" lldp med disable switchport trunk allowed vlan add 4-7,11-13,27,100 ! And the other end of the trunk on core01. interface gigabitethernet1 description sw01 macro description switch switchport trunk allowed vlan add 2-7,11-16,27,100 ! I have a monitor port on core01, thus: core01#sh run int gi12 interface gigabitethernet12 description "monitor port" port monitor GigabitEthernet 1 ! And the monitor port on core01 sees unicast traffic going between net01 and net02, both of which are on sw01! I've verified this with a monitor port on sw01 that sees the net01-net02 unicast traffic leaving via gi1 too. sw01 knows that both of those hosts are on ports that are not its trunk port: :) ratchet$ arp -a | grep net net02.2ndsiteinc.com (10.12.0.11) at 00:0C:29:1A:66:15 [ether] on eth0 net01.2ndsiteinc.com (10.12.0.10) at 00:11:43:D8:9F:94 [ether] on eth0 sw01#sh mac addr addr 00:0C:29:1A:66:15 Aging time is 300 sec Vlan Mac Address Port Type -------- --------------------- ---------- ---------- 12 00:0c:29:1a:66:15 gi11 dynamic sw01#sh mac addr addr 00:11:43:D8:9F:94 Aging time is 300 sec Vlan Mac Address Port Type -------- --------------------- ---------- ---------- 12 00:11:43:d8:9f:94 gi44 dynamic I also brought up an unused port on sw01 on vlan 12, but the unicast traffic was (as best as I could tell) not coming out that port. So it doesn't look like sw01 is pushing it out all its ports, just the right ports and also gi1! I've verified that sw01 is not filling up its address-table: sw01#sh mac addr count This may take some time. Capacity : 8192 Free : 7983 Used : 208 The full configs for both core01 and sw01 are available: core01, sw01. Finally, versions: sw01#sh ver SW version 1.1.2.0 ( date 12-Nov-2011 time 23:34:26 ) Boot version 1.0.0.4 ( date 08-Apr-2010 time 16:37:57 ) HW version V01 core01#sh ver SW version 1.1.2.0 ( date 12-Nov-2011 time 23:34:26 ) Boot version 1.1.0.6 ( date 11-May-2011 time 18:31:00 ) HW version V01 So my understanding is this: sw01 should take unicast traffic for net01 and send it only out net02's port, and vice versa; none of it should go out sw01's uplink. But core01, receiving traffic on gi1 for a host it knows is on gi1, is right in sending it out all of its ports. (That is: sw01 is misbehaving, but core01 is doing what it should given the circumstances.) My question is: Why is sw01 sending that unicast traffic out its uplink, gi1? (And pre-emptively: yes, I know SG300s leave much to be desired, and yes, we should have spanning-tree enabled, but that's where I'm at right now.)

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  • Remote Desktop Services Gateway Issue

    - by AVandelay05
    Alright fellow techies here's the rundown. I have installed Server 2008 r2 Remote Dekstop Services on a VM in my network. I installed the following RD role services: RD Session Host, Licensing, Connection Broker, Gateway, Web Access. When I set things up originally, the gateway server and RDWeb worked as it should locally. After getting things running locally (remoteserver.domainname.local) I wanted to test things externally. From the outside, I couldn't get things running (meaning I could connect to rdweb access externally, but when I tried to run an app I would get the message "can't connect/find computer"). Here's my setup for external access The VM has every RD Services role services installed on it, meaning it acts as gateway, rd web access, session host, licensing, the whole bit. I made a self-signed certificate on the gateway server (gateway.domainname.net is the cert name). Internally, I have a secondary forward-lookup zone called domainname.net with an A record gateway pointing to the local IP of the gateway server. On our public DNS (domainname.net) I have an A record gateway. This is to access the RDWeb externally. In IIS I have the following authentication settings RDWeb: All disabled except for anonymous authentication Rpc: All disabled except for basic and windows RpcWithCert: All disbled except for windows authentication I have the necessary web access config in our sonicwall tz210 (https and rdp, external ip pointing to local ip of rds server) RAP and CAP have the correct user and computer groups, authentication, and allowed devices After all of this, here's what happens accessing externally. I can login correctly to RDWeb Access (I've tried a bogus login, I can't login to it so that's working properly). I see the Apps for use. I click on an app, click connect, the credential window opens, I put in the correct user creds, it tries to connect to the gateway server, but then the cred window comes back in view. I tried to reach a limit of failed logins, but never reached one, haha. So from the same external client machine I try to connect to the gateway through a Remote Desktop connection. I put in the correct gateway settings in the RD window, try to connect and get the same results as I did in RDWeb access. I checked the event logs on the RD Services machine and saw the following event IDs around the time I tried to login externally: ID 6037 with the message "The program svchost.exe, with the assigned process ID 2168, could not authenticate locally by using the target name host/gateway.domainname.net. The target name used is not valid. A target name should refer to one of the local computer names, for example, the DNS host name. Try a different target name." ID 10 RADWebAccess "RD Web Access was unable to access gateway.domainname.net, which is the server that is specified as running the RemoteApp and Desktop Connection Management service. Ensure that the computer account of the RD Web Access server is a member of the TS Web Access Computers security group on gateway.domainname.net" ID 4625 "An account failed to log on. Subject: Security ID: NULL SID Account Name: - Account Domain: - Logon ID: 0x0 Logon Type: 3 Account For Which Logon Failed: Security ID: NULL SID Account Name: Administrator Account Domain: gateway.domainname.net Failure Information: Failure Reason: Unknown user name or bad password. Status: 0xc000006d Sub Status: 0xc000006a Process Information: Caller Process ID: 0x0 Caller Process Name: - Network Information: Workstation Name: USER-LAPTOP Source Network Address: External IP Source Port: 63125 Detailed Authentication Information: Logon Process: NtLmSsp Authentication Package: NTLM Transited Services: - Package Name (NTLM only): - Key Length: 0 This event is generated when a logon request fails. It is generated on the computer where access was attempted. The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe. The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network). The Process Information fields indicate which account and process on the system requested the logon. The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases. The authentication information fields provide detailed information about this specific logon request. - Transited services indicate which intermediate services have participated in this logon request. - Package name indicates which sub-protocol was used among the NTLM protocols." I don't think the VM has a null SID. The SID of the VM and it's physical host have different SIDS. I can access the blank page for rpc externally using the external gateway name. It seems like authentication is a problem. Also, is it a problem that the external name of the gateway server doesn't match the local name? The external name (which the cert is based on) is gateway.domainname.net and the internal name is remoteserver.domainname.local. That's the only thing I can think of that would be the problem, but the external name has to be different from the local right? Internally, I ping gateway.domainname.net and it gives me the correct local IP of the server. Now, there isn't an actual computer name in AD, but I don't know how I would achieve that? I hope I've been clear....any help would be appreciated. I think I'm close to achieving this. :)

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  • FreeBSD high load loopback interface

    - by user1740915
    I have a problem with a FreeBSD server. There is a FreeBSD 9.0 amd64, two network cards em1 (internet), em0 (local network) configured firewall ipfw, natd, squid (not transparent), the server acts as a gateway for access to the Internet. Next problem: upload via squid is very low. At this moment I see next: natd, dhcpd load the cpu at that time when uploading through squid and there are a lot of traffic through the loopback interface. ipfw show output 0100 655389684 36707144666 allow ip from any to any via lo0 00200 0 0 deny ip from any to 127.0.0.0/8 00300 0 0 deny ip from 127.0.0.0/8 to any 00400 0 0 deny ip from any to ::1 00500 0 0 deny ip from ::1 to any 00600 4 292 allow ipv6-icmp from :: to ff02::/16 00700 0 0 allow ipv6-icmp from fe80::/10 to fe80::/10 00800 1 76 allow ipv6-icmp from fe80::/10 to ff02::/16 00900 0 0 allow ipv6-icmp from any to any ip6 icmp6types 1 01000 0 0 allow ipv6-icmp from any to any ip6 icmp6types 2,135,136 01100 1615 76160 deny ip from 192.168.1.1 to any in via em1 01200 0 0 deny ip from 199.69.99.11 to any in via em0 01300 46652 3705426 deny ip from any to 172.16.0.0/12 via em1 01400 3936404 345618870 deny ip from any to 192.168.0.0/16 via em1 01500 4 336 deny ip from any to 0.0.0.0/8 via em1 01600 4129 387621 deny ip from any to 169.254.0.0/16 via em1 01700 0 0 deny ip from any to 192.0.2.0/24 via em1 01800 917566 33777571 deny ip from any to 224.0.0.0/4 via em1 01900 147872 22029252 deny ip from any to 240.0.0.0/4 via em1 02000 1132194739 1190981955947 divert 8668 ip4 from any to any via em1 02100 3 248 deny ip from 172.16.0.0/12 to any via em1 02200 35925 2281289 deny ip from 192.168.0.0/16 to any via em1 02300 1808 122494 deny ip from 0.0.0.0/8 to any via em1 02400 3 174 deny ip from 169.254.0.0/16 to any via em1 02500 0 0 deny ip from 192.0.2.0/24 to any via em1 02600 0 0 deny ip from 224.0.0.0/4 to any via em1 02700 0 0 deny ip from 240.0.0.0/4 to any via em1 02800 960156249 1095316736582 allow tcp from any to any established 02900 64236062 8243196577 allow ip from any to any frag 03000 34 1756 allow tcp from any to me dst-port 25 setup 03100 193 11580 allow tcp from any to me dst-port 53 setup 03200 63 4222 allow udp from any to me dst-port 53 03300 64 8350 allow udp from me 53 to any 03400 417 24140 allow tcp from any to me dst-port 80 setup 03500 211 10472 allow ip from any to me dst-port 3389 setup 05300 77 4488 allow ip from any to me dst-port 1723 setup 05400 3 156 allow ip from any to me dst-port 8443 setup 05500 9882 590596 allow tcp from any to me dst-port 22 setup 05600 1 60 allow ip from any to me dst-port 2000 setup 05700 0 0 allow ip from any to me dst-port 2201 setup 07400 4241779 216690096 deny log logamount 1000 ip4 from any to any in via em1 setup proto tcp 07500 21135656 1048824936 allow tcp from any to any setup 07600 474447 35298081 allow udp from me to any dst-port 53 keep-state 07700 532 40612 allow udp from me to any dst-port 123 keep-state 65535 1990638432 1122305322718 allow ip from any to any systat -ifstat when uploading via squid Load Average ||| Interface Traffic Peak Total tun0 in 79.507 KB/s 232.479 KB/s 42.314 GB out 2.022 MB/s 2.424 MB/s 59.662 GB lo0 in 4.450 MB/s 4.450 MB/s 43.723 GB out 4.450 MB/s 4.450 MB/s 43.723 GB em1 in 2.629 MB/s 2.982 MB/s 464.533 GB out 2.493 MB/s 2.875 MB/s 484.673 GB em0 in 240.458 KB/s 296.941 KB/s 442.368 GB out 512.508 KB/s 850.857 KB/s 416.122 GB top output PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND 66885 root 1 92 0 26672K 2784K CPU3 3 528:43 65.48% natd 9160 dhcpd 1 45 0 31032K 9280K CPU1 1 7:40 32.96% dhcpd 66455 root 1 20 0 18344K 2856K select 1 119:27 1.37% openvpn 16043 squid 1 20 0 44404K 17884K kqread 2 0:22 0.29% squid squid.conf cat /usr/local/etc/squid/squid.conf # # Recommended minimum configuration: # acl manager proto cache_object acl localhost src 127.0.0.1/32 ::1 acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1 # Example rule allowing access from your local networks. # Adapt to list your (internal) IP networks from where browsing # should be allowed acl localnet src 10.0.0.0/8 # RFC1918 possible internal network acl localnet src 172.16.0.0/12 # RFC1918 possible internal network acl localnet src 192.168.0.0/16 # RFC1918 possible internal network acl localnet src fc00::/7 # RFC 4193 local private network range acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines acl SSL_ports port 443 acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl Safe_ports port 70 # gopher acl Safe_ports port 210 # wais acl Safe_ports port 1025-65535 # unregistered ports acl Safe_ports port 280 # http-mgmt acl Safe_ports port 488 # gss-http acl Safe_ports port 591 # filemaker acl Safe_ports port 777 # multiling http acl CONNECT method CONNECT # # Recommended minimum Access Permission configuration: # # Only allow cachemgr access from localhost http_access allow manager localhost http_access deny manager # Deny requests to certain unsafe ports http_access deny !Safe_ports # Deny CONNECT to other than secure SSL ports http_access deny CONNECT !SSL_ports # We strongly recommend the following be uncommented to protect innocent # web applications running on the proxy server who think the only # one who can access services on "localhost" is a local user http_access deny to_localhost # # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS # # Example rule allowing access from your local networks. # Adapt localnet in the ACL section to list your (internal) IP networks # from where browsing should be allowed http_access allow localnet http_access allow localhost # And finally deny all other access to this proxy http_access deny all # Squid normally listens to port 3128 http_port 192.168.1.1:3128 # Uncomment and adjust the following to add a disk cache directory. #cache_dir ufs /var/squid/cache 100 16 256 # Leave coredumps in the first cache dir coredump_dir /var/squid/cache I understand that the traffic passes through the SQUID several times. But can not find why.

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  • Using a WPF ListView as a DataGrid

    - by psheriff
    Many people like to view data in a grid format of rows and columns. WPF did not come with a data grid control that automatically creates rows and columns for you based on the object you pass it. However, the WPF Toolkit can be downloaded from CodePlex.com that does contain a DataGrid control. This DataGrid gives you the ability to pass it a DataTable or a Collection class and it will automatically figure out the columns or properties and create all the columns for you and display the data.The DataGrid control also supports editing and many other features that you might not always need. This means that the DataGrid does take a little more time to render the data. If you want to just display data (see Figure 1) in a grid format, then a ListView works quite well for this task. Of course, you will need to create the columns for the ListView, but with just a little generic code, you can create the columns on the fly just like the WPF Toolkit’s DataGrid. Figure 1: A List of Data using a ListView A Simple ListView ControlThe XAML below is what you would use to create the ListView shown in Figure 1. However, the problem with using XAML is you have to pre-define the columns. You cannot re-use this ListView except for “Product” data. <ListView x:Name="lstData"          ItemsSource="{Binding}">  <ListView.View>    <GridView>      <GridViewColumn Header="Product ID"                      Width="Auto"               DisplayMemberBinding="{Binding Path=ProductId}" />      <GridViewColumn Header="Product Name"                      Width="Auto"               DisplayMemberBinding="{Binding Path=ProductName}" />      <GridViewColumn Header="Price"                      Width="Auto"               DisplayMemberBinding="{Binding Path=Price}" />    </GridView>  </ListView.View></ListView> So, instead of creating the GridViewColumn’s in XAML, let’s learn to create them in code to create any amount of columns in a ListView. Create GridViewColumn’s From Data TableTo display multiple columns in a ListView control you need to set its View property to a GridView collection object. You add GridViewColumn objects to the GridView collection and assign the GridView to the View property. Each GridViewColumn object needs to be bound to a column or property name of the object that the ListView will be bound to. An ADO.NET DataTable object contains a collection of columns, and these columns have a ColumnName property which you use to bind to the GridViewColumn objects. Listing 1 shows a sample of reading and XML file into a DataSet object. After reading the data a GridView object is created. You can then loop through the DataTable columns collection and create a GridViewColumn object for each column in the DataTable. Notice the DisplayMemberBinding property is set to a new Binding to the ColumnName in the DataTable. C#private void FirstSample(){  // Read the data  DataSet ds = new DataSet();  ds.ReadXml(GetCurrentDirectory() + @"\Xml\Product.xml");    // Create the GridView  GridView gv = new GridView();   // Create the GridView Columns  foreach (DataColumn item in ds.Tables[0].Columns)  {    GridViewColumn gvc = new GridViewColumn();    gvc.DisplayMemberBinding = new Binding(item.ColumnName);    gvc.Header = item.ColumnName;    gvc.Width = Double.NaN;    gv.Columns.Add(gvc);  }   // Setup the GridView Columns  lstData.View = gv;  // Display the Data  lstData.DataContext = ds.Tables[0];} VB.NETPrivate Sub FirstSample()  ' Read the data  Dim ds As New DataSet()  ds.ReadXml(GetCurrentDirectory() & "\Xml\Product.xml")   ' Create the GridView  Dim gv As New GridView()   ' Create the GridView Columns  For Each item As DataColumn In ds.Tables(0).Columns    Dim gvc As New GridViewColumn()    gvc.DisplayMemberBinding = New Binding(item.ColumnName)    gvc.Header = item.ColumnName    gvc.Width = [Double].NaN    gv.Columns.Add(gvc)  Next   ' Setup the GridView Columns  lstData.View = gv  ' Display the Data  lstData.DataContext = ds.Tables(0)End SubListing 1: Loop through the DataTable columns collection to create GridViewColumn objects A Generic Method for Creating a GridViewInstead of having to write the code shown in Listing 1 for each ListView you wish to create, you can create a generic method that given any DataTable will return a GridView column collection. Listing 2 shows how you can simplify the code in Listing 1 by setting up a class called WPFListViewCommon and create a method called CreateGridViewColumns that returns your GridView. C#private void DataTableSample(){  // Read the data  DataSet ds = new DataSet();  ds.ReadXml(GetCurrentDirectory() + @"\Xml\Product.xml");   // Setup the GridView Columns  lstData.View =      WPFListViewCommon.CreateGridViewColumns(ds.Tables[0]);  lstData.DataContext = ds.Tables[0];} VB.NETPrivate Sub DataTableSample()  ' Read the data  Dim ds As New DataSet()  ds.ReadXml(GetCurrentDirectory() & "\Xml\Product.xml")   ' Setup the GridView Columns  lstData.View = _      WPFListViewCommon.CreateGridViewColumns(ds.Tables(0))  lstData.DataContext = ds.Tables(0)End SubListing 2: Call a generic method to create GridViewColumns. The CreateGridViewColumns MethodThe CreateGridViewColumns method will take a DataTable as a parameter and create a GridView object with a GridViewColumn object in its collection for each column in your DataTable. C#public static GridView CreateGridViewColumns(DataTable dt){  // Create the GridView  GridView gv = new GridView();  gv.AllowsColumnReorder = true;   // Create the GridView Columns  foreach (DataColumn item in dt.Columns)  {    GridViewColumn gvc = new GridViewColumn();    gvc.DisplayMemberBinding = new Binding(item.ColumnName);    gvc.Header = item.ColumnName;    gvc.Width = Double.NaN;    gv.Columns.Add(gvc);  }   return gv;} VB.NETPublic Shared Function CreateGridViewColumns _  (ByVal dt As DataTable) As GridView  ' Create the GridView  Dim gv As New GridView()  gv.AllowsColumnReorder = True   ' Create the GridView Columns  For Each item As DataColumn In dt.Columns    Dim gvc As New GridViewColumn()    gvc.DisplayMemberBinding = New Binding(item.ColumnName)    gvc.Header = item.ColumnName    gvc.Width = [Double].NaN    gv.Columns.Add(gvc)  Next   Return gvEnd FunctionListing 3: The CreateGridViewColumns method takes a DataTable and creates GridViewColumn objects in a GridView. By separating this method out into a class you can call this method anytime you want to create a ListView with a collection of columns from a DataTable. SummaryIn this blog you learned how to create a ListView that acts like a DataGrid. You are able to use a DataTable as both the source of the data, and for creating the columns for the ListView. In the next blog entry you will learn how to use the same technique, but for Collection classes. NOTE: You can download the complete sample code (in both VB and C#) at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "WPF ListView as a DataGrid" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free eBook on "Fundamentals of N-Tier".

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  • WCF timeouts are a nightmare

    - by Greg
    We have a bunch of WCF services that work almost all of the time, using various bindings, ports, max sizes, etc. The super-frustrating thing about WCF is that when it (rarely) fails, we are powerless to find out why it failed. Sometimes you will get a message that looks like this: System.ServiceModel.CommunicationException: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '01:00:00'. --- System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. The problem is that the local socket timeout it's giving you is merely an attempt to be convenient. It may or may not be the cause of the problem. But OK, sometimes networks have issues. No big deal. We can retry or something. But here's the huge problem. On top of failing to tell you which precisely which timeout (if any) resulted in the failure ("your server-side receive timeout was exceeded," or something, would be helpful), WCF seems to have two types of timeouts. Timeout Type #1) A timeout, that, if increased, would increase the chance of your operation's success. So, the pertinent timeout is an hour, you are uploading a huge file that will take an hour and twenty minutes. It fails. You increase the timeout, it succeeds. I have no no problem with this type of timeout. Timeout Type #2) A timeout which merely defines how long you have to wait for the service to actually fail and give you an error, but modifying the value of this timeout has no impact on the chance of success. Basically, something happens during the first second of the service request which mucks things up. It will never recover. WCF doesn't magically retry the network connection for you. Fine, sometimes establishing a network connection doesn't go well. But, if your timeout is 2 hours, you have to wait 2 whole hours with no chance of it ever working before it finally acknowledges that it didn't work and gives you the error. But the error you see in both cases looks the same. With timeout Type #2, it still looks like you are running into a timeout. But, you could increase all of your timeouts to 4 years, and all it would do is make it take 4 years to get an error message. I know that Type #2 exists because I can do an operation that is known to complete in less than a minute when successful, and have it take 2 hours to fail. But, if I kill it and retry, it succeeds quickly. (If you are wondering why there might be a 2 hour timeout on an operation that takes less than a minute, there are times I run the operation with a much larger file and it could take over an hour.) So, to combat the problem with Type #2, you'd want your timeout to be really quick so you immediately know if there is a problem. Then you can retry. But the insurmountable problem is that because I don't know which timeouts are the cause of failure, I don't know what timeouts are Type #1 and which ones are Type #2. There may be one timeout (let's say the client-side send timeout) that acts like Type #1 in some cases and Type #2 in others. I have no idea, and I have no way of finding out. Does anyone know how to track down Type #2 timeouts so I can set them to low values without having to shorten actual (read: Type #1) timeouts and lower the chance of success? Thank you.

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  • Java Logger API

    - by Koppar
    This is a more like a tip rather than technical write up and serves as a quick intro for newbies. The logger API helps to diagnose application level or JDK level issues at runtime. There are 7 levels which decide the detailing in logging (SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST). Its best to start with highest level and as we narrow down, use more detailed logging for a specific area. SEVERE is the highest and FINEST is the lowest. This may not make sense until we understand some jargon. The Logger class provides the ability to stream messages to an output stream in a format that can be controlled by the user. What this translates to is, I can create a logger with this simple invocation and use it add debug messages in my class: import java.util.logging.*; private static final Logger focusLog = Logger.getLogger("java.awt.focus.KeyboardFocusManager"); if (focusLog.isLoggable(Level.FINEST)) { focusLog.log(Level.FINEST, "Calling peer setCurrentFocusOwner}); LogManager acts like a book keeper and all the getLogger calls are forwarded to LogManager. The LogManager itself is a singleton class object which gets statically initialized on JVM start up. More on this later. If there is no existing logger with the given name, a new one is created. If there is one (and not yet GC’ed), then the existing Logger object is returned. By default, a root logger is created on JVM start up. All anonymous loggers are made as the children of the root logger. Named loggers have the hierarchy as per their name resolutions. Eg: java.awt.focus is the parent logger for java.awt.focus.KeyboardFocusManager etc. Before logging any message, the logger checks for the log level specified. If null is specified, the log level of the parent logger will be set. However, if the log level is off, no log messages would be written, irrespective of the parent’s log level. All the messages that are posted to the Logger are handled as a LogRecord object.i.e. FocusLog.log would create a new LogRecord object with the log level and message as its data members). The level of logging and thread number are also tracked. LogRecord is passed on to all the registered Handlers. Handler is basically a means to output the messages. The output may be redirected to either a log file or console or a network logging service. The Handler classes use the LogManager properties to set filters and formatters. During initialization or JVM start up, LogManager looks for logging.properties file in jre/lib and sets the properties if the file is provided. An alternate location for properties file can also be specified by setting java.util.logging.config.file system property. This can be set in Java Control Panel ? Java ? Runtime parameters as -Djava.util.logging.config.file = <mylogfile> or passed as a command line parameter java -Djava.util.logging.config.file = C:/Sunita/myLog The redirection of logging depends on what is specified rather registered as a handler with JVM in the properties file. java.util.logging.ConsoleHandler sends the output to system.err and java.util.logging.FileHandler sends the output to file. File name of the log file can also be specified. If you prefer XML format output, in the configuration file, set java.util.logging.FileHandler.formatter = java.util.logging.XMLFormatter and if you prefer simple text, set set java.util.logging.FileHandler.formatter =java.util.logging.SimpleFormatter Below is the default logging Configuration file: ############################################################ # Default Logging Configuration File # You can use a different file by specifying a filename # with the java.util.logging.config.file system property. # For example java -Djava.util.logging.config.file=myfile ############################################################ ############################################################ # Global properties ############################################################ # "handlers" specifies a comma separated list of log Handler # classes. These handlers will be installed during VM startup. # Note that these classes must be on the system classpath. # By default we only configure a ConsoleHandler, which will only # show messages at the INFO and above levels. handlers= java.util.logging.ConsoleHandler # To also add the FileHandler, use the following line instead. #handlers= java.util.logging.FileHandler, java.util.logging.ConsoleHandler # Default global logging level. # This specifies which kinds of events are logged across # all loggers. For any given facility this global level # can be overriden by a facility specific level # Note that the ConsoleHandler also has a separate level # setting to limit messages printed to the console. .level= INFO ############################################################ # Handler specific properties. # Describes specific configuration info for Handlers. ############################################################ # default file output is in user's home directory. java.util.logging.FileHandler.pattern = %h/java%u.log java.util.logging.FileHandler.limit = 50000 java.util.logging.FileHandler.count = 1 java.util.logging.FileHandler.formatter = java.util.logging.XMLFormatter # Limit the message that are printed on the console to INFO and above. java.util.logging.ConsoleHandler.level = INFO java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter ############################################################ # Facility specific properties. # Provides extra control for each logger. ############################################################ # For example, set the com.xyz.foo logger to only log SEVERE # messages: com.xyz.foo.level = SEVERE Since I primarily use this method to track focus issues, here is how I get detailed awt focus related logging. Just set the logger name to java.awt.focus.level=FINEST and change the default log level to FINEST. Below is a basic sample program. The sample programs are from http://www2.cs.uic.edu/~sloan/CLASSES/java/ and have been modified to illustrate the logging API. By changing the .level property in the logging.properties file, one can control the output written to the logs. To play around with the example, try changing the levels in the logging.properties file and notice the difference in messages going to the log file. Example --------KeyboardReader.java------------------------------------------------------------------------------------- import java.io.*; import java.util.*; import java.util.logging.*; public class KeyboardReader { private static final Logger mylog = Logger.getLogger("samples.input"); public static void main (String[] args) throws java.io.IOException { String s1; String s2; double num1, num2, product; // set up the buffered reader to read from the keyboard BufferedReader br = new BufferedReader (new InputStreamReader (System.in)); System.out.println ("Enter a line of input"); s1 = br.readLine(); if (mylog.isLoggable(Level.SEVERE)) { mylog.log (Level.SEVERE,"The line entered is " + s1); } if (mylog.isLoggable(Level.INFO)) { mylog.log (Level.INFO,"The line has " + s1.length() + " characters"); } if (mylog.isLoggable(Level.FINE)) { mylog.log (Level.FINE,"Breaking the line into tokens we get:"); } int numTokens = 0; StringTokenizer st = new StringTokenizer (s1); while (st.hasMoreTokens()) { s2 = st.nextToken(); numTokens++; if (mylog.isLoggable(Level.FINEST)) { mylog.log (Level.FINEST, " Token " + numTokens + " is: " + s2); } } } } ----------MyFileReader.java---------------------------------------------------------------------------------------- import java.io.*; import java.util.*; import java.util.logging.*; public class MyFileReader extends KeyboardReader { private static final Logger mylog = Logger.getLogger("samples.input.file"); public static void main (String[] args) throws java.io.IOException { String s1; String s2; // set up the buffered reader to read from the keyboard BufferedReader br = new BufferedReader (new FileReader ("MyFileReader.txt")); s1 = br.readLine(); if (mylog.isLoggable(Level.SEVERE)) { mylog.log (Level.SEVERE,"ATTN The line is " + s1); } if (mylog.isLoggable(Level.INFO)) { mylog.log (Level.INFO, "The line has " + s1.length() + " characters"); } if (mylog.isLoggable(Level.FINE)) { mylog.log (Level.FINE,"Breaking the line into tokens we get:"); } int numTokens = 0; StringTokenizer st = new StringTokenizer (s1); while (st.hasMoreTokens()) { s2 = st.nextToken(); numTokens++; if (mylog.isLoggable(Level.FINEST)) { mylog.log (Level.FINEST,"Breaking the line into tokens we get:"); mylog.log (Level.FINEST," Token " + numTokens + " is: " + s2); } } //end of while } // end of main } // end of class ----------MyFileReader.txt------------------------------------------------------------------------------------------ My first logging example -------logging.properties------------------------------------------------------------------------------------------- handlers= java.util.logging.ConsoleHandler, java.util.logging.FileHandler .level= FINEST java.util.logging.FileHandler.pattern = java%u.log java.util.logging.FileHandler.limit = 50000 java.util.logging.FileHandler.count = 1 java.util.logging.FileHandler.formatter = java.util.logging.SimpleFormatter java.util.logging.ConsoleHandler.level = FINEST java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter java.awt.focus.level=ALL ------Output log------------------------------------------------------------------------------------------- May 21, 2012 11:44:55 AM MyFileReader main SEVERE: ATTN The line is My first logging example May 21, 2012 11:44:55 AM MyFileReader main INFO: The line has 24 characters May 21, 2012 11:44:55 AM MyFileReader main FINE: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 1 is: My May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 2 is: first May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 3 is: logging May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 4 is: example Invocation command: "C:\Program Files (x86)\Java\jdk1.6.0_29\bin\java.exe" -Djava.util.logging.config.file=logging.properties MyFileReader References Further technical details are available here: http://docs.oracle.com/javase/1.4.2/docs/guide/util/logging/overview.html#1.0 http://docs.oracle.com/javase/1.4.2/docs/api/java/util/logging/package-summary.html http://www2.cs.uic.edu/~sloan/CLASSES/java/

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  • WPF ListView as a DataGrid – Part 2

    - by psheriff
    In my last blog post I showed you how to create GridViewColumn objects on the fly from the meta-data in a DataTable. By doing this you can create columns for a ListView at runtime instead of having to pre-define each ListView for each different DataTable. Well, many of us use collections of our classes and it would be nice to be able to do the same thing for our collection classes as well. This blog post will show you one approach for using collection classes as the source of the data for your ListView.  Figure 1: A List of Data using a ListView Load Property NamesYou could use reflection to gather the property names in your class, however there are two things wrong with this approach. First, reflection is too slow, and second you may not want to display all your properties from your class in the ListView. Instead of reflection you could just create your own custom collection class of PropertyHeader objects. Each PropertyHeader object will contain a property name and a header text value at a minimum. You could add a width property if you wanted as well. All you need to do is to create a collection of property header objects where each object represents one column in your ListView. Below is a simple example: PropertyHeaders coll = new PropertyHeaders(); coll.Add(new PropertyHeader("ProductId", "Product ID"));coll.Add(new PropertyHeader("ProductName", "Product Name"));coll.Add(new PropertyHeader("Price", "Price")); Once you have this collection created, you could pass this collection to a method that would create the GridViewColumn objects based on the information in this collection. Below is the full code for the PropertyHeader class. Besides the PropertyName and Header properties, there is a constructor that will allow you to set both properties when the object is created. C#public class PropertyHeader{  public PropertyHeader()  {  }   public PropertyHeader(string propertyName, string headerText)  {    PropertyName = propertyName;    HeaderText = headerText;  }   public string PropertyName { get; set; }  public string HeaderText { get; set; }} VB.NETPublic Class PropertyHeader  Public Sub New()  End Sub   Public Sub New(ByVal propName As String, ByVal header As String)    PropertyName = propName    HeaderText = header  End Sub   Private mPropertyName As String  Private mHeaderText As String   Public Property PropertyName() As String    Get      Return mPropertyName    End Get    Set(ByVal value As String)      mPropertyName = value    End Set  End Property   Public Property HeaderText() As String    Get      Return mHeaderText    End Get    Set(ByVal value As String)      mHeaderText = value    End Set  End PropertyEnd Class You can use a Generic List class to create a collection of PropertyHeader objects as shown in the following code. C#public class PropertyHeaders : List<PropertyHeader>{} VB.NETPublic Class PropertyHeaders  Inherits List(Of PropertyHeader)End Class Create Property Header Objects You need to create a method somewhere that will create and return a collection of PropertyHeader objects that will represent the columns you wish to add to your ListView prior to binding your collection class to that ListView. Below is a sample method called GetProperties that builds a list of PropertyHeader objects with properties and headers for a Product object. C#public PropertyHeaders GetProperties(){  PropertyHeaders coll = new PropertyHeaders();   coll.Add(new PropertyHeader("ProductId", "Product ID"));  coll.Add(new PropertyHeader("ProductName", "Product Name"));  coll.Add(new PropertyHeader("Price", "Price"));   return coll;} VB.NETPublic Function GetProperties() As PropertyHeaders  Dim coll As New PropertyHeaders()   coll.Add(New PropertyHeader("ProductId", "Product ID"))  coll.Add(New PropertyHeader("ProductName", "Product Name"))  coll.Add(New PropertyHeader("Price", "Price"))   Return collEnd Function WPFListViewCommon Class Now that you have a collection of PropertyHeader objects you need a method that will create a GridView and a collection of GridViewColumn objects based on this PropertyHeader collection. Below is a static/Shared method that you might put into a class called WPFListViewCommon. C#public static GridView CreateGridViewColumns(  PropertyHeaders properties){  GridView gv;  GridViewColumn gvc;   // Create the GridView  gv = new GridView();  gv.AllowsColumnReorder = true;   // Create the GridView Columns  foreach (PropertyHeader item in properties)  {    gvc = new GridViewColumn();    gvc.DisplayMemberBinding = new Binding(item.PropertyName);    gvc.Header = item.HeaderText;    gvc.Width = Double.NaN;    gv.Columns.Add(gvc);  }   return gv;} VB.NETPublic Shared Function CreateGridViewColumns( _    ByVal properties As PropertyHeaders) As GridView  Dim gv As GridView  Dim gvc As GridViewColumn   ' Create the GridView  gv = New GridView()  gv.AllowsColumnReorder = True   ' Create the GridView Columns  For Each item As PropertyHeader In properties    gvc = New GridViewColumn()    gvc.DisplayMemberBinding = New Binding(item.PropertyName)    gvc.Header = item.HeaderText    gvc.Width = [Double].NaN    gv.Columns.Add(gvc)  Next   Return gvEnd Function Build the Product Screen To build the window shown in Figure 1, you might write code like the following: C#private void CollectionSample(){  Product prod = new Product();   // Setup the GridView Columns  lstData.View = WPFListViewCommon.CreateGridViewColumns(       prod.GetProperties());  lstData.DataContext = prod.GetProducts();} VB.NETPrivate Sub CollectionSample()  Dim prod As New Product()   ' Setup the GridView Columns  lstData.View = WPFListViewCommon.CreateGridViewColumns( _       prod.GetProperties())  lstData.DataContext = prod.GetProducts()End Sub The Product class contains a method called GetProperties that returns a PropertyHeaders collection. You pass this collection to the WPFListViewCommon’s CreateGridViewColumns method and it will create a GridView for the ListView. When you then feed the DataContext property of the ListView the Product collection the appropriate columns have already been created and data bound. Summary In this blog you learned how to create a ListView that acts like a DataGrid using a collection class. While it does take a little code to do this, it is an alternative to creating each GridViewColumn in XAML. This gives you a lot of flexibility. You could even read in the property names and header text from an XML file for a truly configurable ListView. NOTE: You can download the complete sample code (in both VB and C#) at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "WPF ListView as a DataGrid – Part 2" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free eBook on "Fundamentals of N-Tier".  

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  • How do you mock ViewModel Commands using moq?

    - by devnet247
    Hi I might be approaching this all wrong.But please help me to understand. I really want to TDD building wpf application using Moq. I would like to mock the viewmodel. Application Show a list of contacts and when you double click on a contact it shows the contact. Test Moq GetContactsCommand.Test it has been called. Test that you get a list of contacts. Not sure how to mock the viewModel and it's commands can you correct me? So I have started to do the following [Test] public void Should_be_able_to_mock_getContactsCommand_and_get_a_list_of_contacts() { //Arrange var expectedContacts = new ObservableCollection<ContactViewModel> { new ContactViewModel(new ContactModel { FirstName = "Jo", LastName = "Bloggs", Email = "[email protected]" }), new ContactViewModel(new ContactModel { FirstName = "Mary", LastName = "Bloggs", Email = "[email protected]" }) }; var mock = new Mock<IContactListViewModel>(); mock.SetupGet(x => x.GetContactsCommand).Verifiable(); mock.SetupGet(x => x.Contacts).Returns(expectedContacts); //Act //? //assert mock.VerifySet(x => x.Contacts, Times.AtLeastOnce()); mock.Object.Contacts.Count.ShouldEqual(expectedContacts.Count); } public interface IContactListViewModel { ObservableCollection<ContactViewModel> Contacts { get; set; } ICommand GetContactsCommand{ get; } } public interface IContactModel { string FirstName { get; set; } string LastName { get; set; } string Email { get; set; } } public class ContactModel : IContactModel { public string FirstName { get; set; } public string LastName { get; set; } public string Email { get; set; } } public class ContactViewModel : ViewModelBase { private readonly ContactModel _contactModel; public ContactViewModel(ContactModel contactModel) { _contactModel = contactModel; } public string FirstName { get { return _contactModel.FirstName; } set { _contactModel.FirstName = value; OnPropertyChanged("FirstName"); } } public string LastName { get { return _contactModel.LastName; } set { _contactModel.LastName = value; OnPropertyChanged("LastName"); } } public string Email { get { return _contactModel.Emai; } set { _contactModel.Email = value; OnPropertyChanged("Email"); } } } public class ContactListViewModel : ViewModelBase, IContactListViewModel { private ObservableCollection<ContactViewModel> _contacts; public ObservableCollection<ContactViewModel> Contacts { get { return _contacts; } set { _contacts = value; OnPropertyChanged("Contacts"); } } private RelayCommand _getContactsCommand; public ICommand GetContactsCommand { get { return _getContactsCommand ?? (_getContactsCommand = new RelayCommand(x => GetContacts(), x => CanGetContacts)); } } private static bool CanGetContacts { get { return true; } } private void GetContacts() { //pretend we are going to the service or db whatever Contacts = new ObservableCollection<ContactViewModel> { new ContactViewModel(new ContactModel { FirstName = "Jo", LastName = "Bloggs", Email = "[email protected]" }), new ContactViewModel(new ContactModel { FirstName = "Mary", LastName = "Bloggs", Email = "[email protected]" }) }; } }

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