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  • Setting up a DNS name server for a mass virtual host with Bind9

    - by Dez
    I am trying to set up a chrooted DNS name server in a local LAN like this everyone connected in the LAN can have access to the mass virtual hosts defined for a development ambience without having to edit manually their local /etc/hosts one by one. The mass virtual host is named example.user.dev (VirtualDocumentRoot /home/user/example ) and example.test (DocumentRoot /var/www/example). I set up everything and the /var/log/syslog doesn't show any error, but when checking the DNS with: host -v example.test Doesn't find the host. Also using the dig command I don't receive answer. dig -x example.test ; << DiG 9.5.1-P3 << -x imprimere ;; global options: printcmd ;; Got answer: ;; -HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 47844 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;imprimere.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: in-addr.arpa. 600 IN SOA a.root-servers.net. dns-ops.arin.net. 2010042604 1800 900 691200 10800 ;; Query time: 108 msec ;; SERVER: 80.58.0.33#53(80.58.0.33) ;; WHEN: Mon Apr 26 11:15:53 2010 ;; MSG SIZE rcvd: 107 My configuration is the following: /etc/bind/named.conf.local zone "example.test" { type master; allow-query { any; }; file "/etc/bind/zones/master_example.test"; notify yes; }; zone "1.168.192.in-addr.arpa" { type master; allow-query { any; }; file "/etc/bind/zones/master_1.168.192.in-addr.arpa"; notify yes; }; /etc/bind/named.conf.options Note: We have an static IP address so I forward the querys to DNS server to said IP address. options{ directory "/var/cache/bind"; forwarders { 80.34.100.160; }; auth-nxdomain no; listen-on-v6 { any; }; }; /etc/bind/zones/master_example.test $ORIGIN example.test. $TTL 86400 @ IN SOA example.test. root.example.test. ( 201004227 ; serial 28800 ; refresh 14400 ; retry 3600000 ; expire 86400 ) ; min ; TXT "example.test, DNS service" @ IN NS example.test. localhost A 127.0.0.1 example.test. A 192.168.1.52 example A 192.168.1.52 www CNAME example.test. /etc/hosts 127.0.0.1 localhost example 192.168.1.52 localhost example example.test /etc/resolv.conf Note: For Bind I just added the 3 last lines. nameserver 80.58.0.33 nameserver 80.58.61.250 nameserver 80.58.61.254 search example.test search example nameserver 192.168.1.52

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  • DNS Server Behind NAT

    - by Bryan
    I've got a Bind 9 DNS server sitting behind a NAT firewall, assume the Internet facing IP is 1.2.3.4 There are no restrictions on outgoing traffic, and port 53 (TCP/UDP) is forwarded from 1.2.3.4 to the internal DNS server (10.0.0.1). There are no IP Tables rules on either the VPS or the internal Bind 9 server. From a remote Linux VPS located elsewhere on the internet, nslookup works fine # nslookup foo.example.com 1.2.3.4 Server: 1.2.3.4 Address: 1.2.3.4#53 Name: foo.example.com Addresss: 9.9.9.9 However, when using the host command on the remote VPS, I receive the following output: # host foo.example.com 1.2.3.4 ;; reply from unexpected source: 1.2.3.4#13731, expected 1.2.3.4#53 ;; reply from unexpected source: 1.2.3.4#13731, expected 1.2.3.4#53 ;; connection timed out; no servers could be reached. From the VPS, I can establish a connection (using telnet) to 1.2.3.4:53 From the internal DNS server (10.0.0.1), the host command appears to be fine: # host foo.example.com 127.0.0.1 Using domain server: Name: 127.0.0.1 Address: 127.0.0.1#53 Aliases: foo.example.com has address 9.9.9.9 Any suggestions as to why the host command on my VPS is complaining about the reply coming back from another port, and what can I do to fix this? Further info: From a windows host external to the network >nslookup foo.example.com 1.2.3.4 DNS request timeout timeout was 2 seconds Server: UnKnown Address: 1.2.3.4 DNS request timed out. timeout was 2 seconds DNS request timed out. timeout was 2 seconds DNS request timed out. timeout was 2 seconds DNS request timed out. timeout was 2 seconds *** Request to UnKnown timed-out This is a default install of bind from Ubuntu 12.04 LTS, with around 11 zones configured. $ named -v BIND 9.8.1-P1 TCP Dump (filtered) from internal DNS server 20:36:29.175701 IP pc.external.com.57226 > dns.example.com.domain: 1+ PTR? 4.3.2.1.in-addr.arpa. (45) 20:36:29.175948 IP dns.example.com.domain > pc.external.com.57226: 1 Refused- 0/0/0 (45) 20:36:31.179786 IP pc.external.com.57227 > dns.example.com.domain: 2+[|domain] 20:36:31.179960 IP dns.example.com.domain > pc.external.com.57227: 2 Refused-[|domain] 20:36:33.180653 IP pc.external.com.57228 > dns.example.com.domain: 3+[|domain] 20:36:33.180906 IP dns.example.com.domain > pc.external.com.57228: 3 Refused-[|domain] 20:36:35.185182 IP pc.external.com.57229 > dns.example.com.domain: 4+ A? foo.example.com. (45) 20:36:35.185362 IP dns.example.com.domain > pc.external.com.57229: 4*- 1/1/1 (95) 20:36:37.182844 IP pc.external.com.57230 > dns.example.com.domain: 5+ AAAA? foo.example.com. (45) 20:36:37.182991 IP dns.example.com.domain > pc.external.com.57230: 5*- 0/1/0 (119) TCP Dump from client during query 21:24:52.054374 IP pc.external.com.43845 > dns.example.com.53: 6142+ A? foo.example.com. (45) 21:24:52.104694 IP dns.example.com.29242 > pc.external.com.43845: UDP, length 95

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  • Bypass DNSSEC for local Stub zones

    - by Starsky
    I am using bind 9.9.2 as a DNSSEC validating recursive resolver in an Internet DMZ. I want to point to my internal DNS servers as stub zones (ideally) or anything except slave zones (to avoid very large zone transfers). We use a routable ip space for our Internal addressing. Sorry if I am using an IP space that you own in my example, but 167.x.x.x is the first zone I found that fits my issue. E.G dnssec-enable yes; dnssec-validation yes; dnssec-accept-expired no; zone "16.172.in-addr.arpa" { type stub; masters { 167.255.1.53; } } zone "myzone.com" in { type stub; masters { 167.255.1.53; } } When queries hit the DNS server, they attempt at being validated, and fail because 167.in-addr.arpa HAS an RRSIG record, but sub zones do not (and should not!). Google dns is used in this example, but in reality it would be my recursive resolver. @8.8.8.8 -x 167.255.1.53 +dnssec ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 17488 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 6, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags: do; udp: 512 ;; QUESTION SECTION: ;53.1.255.167.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: 167.in-addr.arpa. 1800 IN SOA z.arin.net. dns-ops.arin.net. 2013100713 1800 900 691200 10800 167.in-addr.arpa. 1800 IN RRSIG SOA 5 3 86400 20131017160124 20131007160124 812 167.in-addr.arpa. Lcl8sCps7LapnAj4n403KXx7A3GO7+2z/9Q2R2mwkh9FL26iDx7GlU4+ NufGd92IEJCdBu9IgcZP4I9QcKi8DI28og27WrfKd5moSl/STj02GliS qPTfNiewmTTIDw5++IlhITbp+CoJuZCRCdDbyWKmd5NSLcbskAwbCVlO vVA= 167.in-addr.arpa. 10800 IN NSEC 1.167.in-addr.arpa. NS SOA TXT RRSIG NSEC DNSKEY 167.in-addr.arpa. 10800 IN RRSIG NSEC 5 3 10800 20131017160124 20131007160124 812 167.in-addr.arpa. XALsd59i+XGvCIzjhTUFXcr11/M8prcaaPQ5yFSbvP9TzqjJ3wpizvH6 202MdrIWbsT1Dndri49lHKAXgBQ5OOsUmOh+eoRYR5okxRO4VLc5Tkze Gh0fQLcwGXPuv9A4SFNIrNyi3XU4Qvq0cViKXIuEGTa3C+zMPuvc0her oKk= 254.167.in-addr.arpa. 10800 IN NSEC 26.167.in-addr.arpa. NS RRSIG NSEC 254.167.in-addr.arpa. 10800 IN RRSIG NSEC 5 4 10800 20131017160124 20131007160124 812 167.in-addr.arpa. xnsLBTnPhdyABdvqtEHPxa6Y6NASfYAWfW1yYlNliTyV8TFeNOqewjwj nY43CWD77ftFDDQTLFEOPpV5vwmnUGYTRztK+kB5UrlflhPgiqYiBaBD RQaFQ8DIKaof8/snusZjK7aNmfe09t9gRcaX/pXn3liKz7m/ggxZi0f9 xo0= ;; Query time: 31 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: Mon Oct 7 16:52:59 2013 ;; MSG SIZE rcvd: 722 Is there a way to bypass DNSSEC validation for specific zones? Any zone that I host internally, I do not want DNSSEC validation performed on. I have only see this interfere w/ certain reverse zones where the top level has DS/RRSIG records. Thanks.

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  • Setting up home DNS with Ubuntu Server

    - by Zeophlite
    I have a webserver (with static IP 192.168.1.5), and I want to have my machines on my local network to be able to access it without modifying /etc/hosts (or equivalent for Windows/OSX). My router has Primary DNS server 192.168.1.5 Secondary DNS server 8.8.8.8 (Google's public DNS). Nginx is set up to server websites externally as *.example.com Internally, I want *.example.local to point to the server. My webserver has BIND9 installed, but I'm unsure of the settings. I've been through various contradicting tutorials, and so most of my settings have been clobbered. I've stripped out the lines which I'm confused about. The tutorials I looked at are http://tech.surveypoint.com/blog/installing-a-local-dns-server-behind-a-hardware-router/ and http://ubuntuforums.org/showthread.php?t=236093 . They mostly differ on what should be put in /etc/bind/zones/db.example.local and /etc/bind/zones/db.192, so I've left the conflicting lines out below. Can someone suggest what the correct lines are to give my above behaviour (namely *.example.local pointing to 192.168.1.5)? /etc/network/interfaces auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.1.5 netmask 255.255.255.0 broadcast 192.168.1.255 gateway 192.168.1.254 /etc/hostname avalon /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN /etc/bind/named.conf.options options { directory "/var/cache/bind"; forwarders { 8.8.8.8; 8.8.4.4; }; dnssec-validation auto; auth-nxdomain no; # conform to RFC1035 listen-on-v6 { any; }; }; /etc/bind/named.conf.local zone "example.local" { type master; file "/etc/bind/zones/db.example.local"; }; zone "1.168.192.in-addr.arpa" { type master; file "/etc/bind/zones/db.192"; }; /etc/bind/zones/db.example.local $TTL 604800 @ IN SOA avalon.example.local. webadmin.example.local. ( 5 ; Serial, increment each edit 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL /etc/bind/zones/db.192 $TTL 604800 @ IN SOA avalon.example.local. webadmin.example.local. ( 4 ; Serial, increment each edit 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; What do I need to add to the above files so that on a laptop on the internal network, I can type in webapp.example.local, and be served by my webserver? EDIT I made several changes to the above files on the webserver. /etc/network/interfaces (end of file) dns-nameservers 127.0.0.1 dns-search example.local /etc/bind/zones/db.example.local (end of file) @ IN NS avalon.example.local. @ IN A 192.168.1.5 avalon IN A 192.168.1.5 webapp IN A 192.168.1.5 www IN CNAME 192.168.1.5 /etc/bind/zones/db.192 (end of file) IN NS avalon.example.local. 73 IN PTR avalon.example.local. As a side note, my spare Win7 machine was able to connect directly to webapp.example.local, but for a Ubuntu 13.10 machine, I had to make the following changes as well (not on the webserver, but on a separate machine): /etc/nsswitch.conf before hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4 after hosts: files dns /etc/NetworkManager/NetworkManager.conf before dns=dnsmasq after #dns=dnsmasq The issue remains that its not wildcard DNS, and so I have to add entries to /etc/bind/zones/db.example.local for webapp1, webapp2, ...

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  • SQLAlchemy session management in long-running process

    - by codeape
    Scenario: A .NET-based application server (Wonderware IAS/System Platform) hosts automation objects that communicate with various equipment on the factory floor. CPython is hosted inside this application server (using Python for .NET). The automation objects have scripting functionality built-in (using a custom, .NET-based language). These scripts call Python functions. The Python functions are part of a system to track Work-In-Progress on the factory floor. The purpose of the system is to track the produced widgets along the process, ensure that the widgets go through the process in the correct order, and check that certain conditions are met along the process. The widget production history and widget state is stored in a relational database, this is where SQLAlchemy plays its part. For example, when a widget passes a scanner, the automation software triggers the following script (written in the application server's custom scripting language): ' wiget_id and scanner_id provided by automation object ' ExecFunction() takes care of calling a CPython function retval = ExecFunction("WidgetScanned", widget_id, scanner_id); ' if the python function raises an Exception, ErrorOccured will be true ' in this case, any errors should cause the production line to stop. if (retval.ErrorOccured) then ProductionLine.Running = False; InformationBoard.DisplayText = "ERROR: " + retval.Exception.Message; InformationBoard.SoundAlarm = True end if; The script calls the WidgetScanned python function: # pywip/functions.py from pywip.database import session from pywip.model import Widget, WidgetHistoryItem from pywip import validation, StatusMessage from datetime import datetime def WidgetScanned(widget_id, scanner_id): widget = session.query(Widget).get(widget_id) validation.validate_widget_passed_scanner(widget, scanner) # raises exception on error widget.history.append(WidgetHistoryItem(timestamp=datetime.now(), action=u"SCANNED", scanner_id=scanner_id)) widget.last_scanner = scanner_id widget.last_update = datetime.now() return StatusMessage("OK") # ... there are a dozen similar functions My question is: How do I best manage SQLAlchemy sessions in this scenario? The application server is a long-running process, typically running months between restarts. The application server is single-threaded. Currently, I do it the following way: I apply a decorator to the functions I make avaliable to the application server: # pywip/iasfunctions.py from pywip import functions def ias_session_handling(func): def _ias_session_handling(*args, **kwargs): try: retval = func(*args, **kwargs) session.commit() return retval except: session.rollback() raise return _ias_session_handling # ... actually I populate this module with decorated versions of all the functions in pywip.functions dynamically WidgetScanned = ias_session_handling(functions.WidgetScanned) Question: Is the decorator above suitable for handling sessions in a long-running process? Should I call session.remove()? The SQLAlchemy session object is a scoped session: # pywip/database.py from sqlalchemy.orm import scoped_session, sessionmaker session = scoped_session(sessionmaker()) I want to keep the session management out of the basic functions. For two reasons: There is another family of functions, sequence functions. The sequence functions call several of the basic functions. One sequence function should equal one database transaction. I need to be able to use the library from other environments. a) From a TurboGears web application. In that case, session management is done by TurboGears. b) From an IPython shell. In that case, commit/rollback will be explicit. (I am truly sorry for the long question. But I felt I needed to explain the scenario. Perhaps not necessary?)

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  • Preventing multiple repeat selection of synchronized Controls ?

    - by BillW
    The working code sample here synchronizes (single) selection in a TreeView, ListView, and ComboBox via the use of lambda expressions in a dictionary where the Key in the dictionary is a Control, and the Value of each Key is an Action<int. Where I am stuck is that I am getting multiple repetitions of execution of the code that sets the selection in the various controls in a way that's unexpected : it's not recursing : there's no StackOverFlow error happening; but, I would like to figure out why the current strategy for preventing multiple selection of the same controls is not working. Perhaps the real problem here is distinguishing between a selection update triggered by the end-user and a selection update triggered by the code that synchronizes the other controls ? Note: I've been experimenting with using Delegates, and forms of Delegates like Action<T>, to insert executable code in Dictionaries : I "learn best" by posing programming "challenges" to myself, and implementing them, as well as studying, at the same time, the "golden words" of luminaries like Skeet, McDonald, Liberty, Troelsen, Sells, Richter. Note: Appended to this question/code, for "deep background," is a statement of how I used to do things in pre C#3.0 days where it seemed like I did need to use explicit measures to prevent recursion when synchronizing selection. Code : Assume a WinForms standard TreeView, ListView, ComboBox, all with the same identical set of entries (i.e., the TreeView has only root nodes; the ListView, in Details View, has one Column). private Dictionary<Control, Action<int>> ControlToAction = new Dictionary<Control, Action<int>>(); private void Form1_Load(object sender, EventArgs e) { // add the Controls to be synchronized to the Dictionary // with appropriate Action<int> lambda expressions ControlToAction.Add(treeView1, (i => { treeView1.SelectedNode = treeView1.Nodes[i]; })); ControlToAction.Add(listView1, (i => { listView1.Items[i].Selected = true; })); ControlToAction.Add(comboBox1, (i => { comboBox1.SelectedIndex = i; })); } private void synchronizeSelection(int i, Control currentControl) { foreach(Control theControl in ControlToAction.Keys) { // skip the 'current control' if (theControl == currentControl) continue; // for debugging only Console.WriteLine(theControl.Name + " synchronized"); // execute the Action<int> associated with the Control ControlToAction[theControl](i); } } private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { synchronizeSelection(e.Node.Index, treeView1); } private void listView1_SelectedIndexChanged(object sender, EventArgs e) { // weed out ListView SelectedIndexChanged firing // with SelectedIndices having a Count of #0 if (listView1.SelectedIndices.Count > 0) { synchronizeSelection(listView1.SelectedIndices[0], listView1); } } private void comboBox1_SelectedValueChanged(object sender, EventArgs e) { if (comboBox1.SelectedIndex > -1) { synchronizeSelection(comboBox1.SelectedIndex, comboBox1); } } background : pre C# 3.0 Seems like, back in pre C# 3.0 days, I was always using a boolean flag to prevent recursion when multiple controls were updated. For example, I'd typically have code like this for synchronizing a TreeView and ListView : assuming each Item in the ListView was synchronized with a root-level node of the TreeView via a common index : // assume ListView is in 'Details View,' has a single column, // MultiSelect = false // FullRowSelect = true // HideSelection = false; // assume TreeView // HideSelection = false // FullRowSelect = true // form scoped variable private bool dontRecurse = false; private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { if(dontRecurse) return; dontRecurse = true; listView1.Items[e.Node.Index].Selected = true; dontRecurse = false; } private void listView1_SelectedIndexChanged(object sender, EventArgs e) { if(dontRecurse) return // weed out ListView SelectedIndexChanged firing // with SelectedIndices having a Count of #0 if (listView1.SelectedIndices.Count > 0) { dontRecurse = true; treeView1.SelectedNode = treeView1.Nodes[listView1.SelectedIndices[0]]; dontRecurse = false; } } Then it seems, somewhere around FrameWork 3~3.5, I could get rid of the code to suppress recursion, and there was was no recursion (at least not when synchronizing a TreeView and a ListView). By that time it had become a "habit" to use a boolean flag to prevent recursion, and that may have had to do with using a certain third party control.

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  • SharePoint Feature suggestion

    - by barathan
    I have written a feature(Site scoped) that adds custom menu items to the New Menu and EditControlBlock of document library. These menu items should show up only when the user has add and edit permissions for that document library. If he selected the menu, url is redirected to my webpart. Webpart is deployed in site collection. To do this i have two way. I mentioned in as case 1 & case 2. But in the both cases i failed to fulfill my requirement Below are the sample entries in Feature and Element manifest file I am passing the current location to sourceurl in order to get the folder url <?xml version="1.0" encoding="utf-8" ?> <Feature Id="59bba8e7-0cfc-46e3-9285-4597f8085e76" Title="My Custom Menus" Scope="Site" xmlns="http://schemas.microsoft.com/sharepoint/"> <ElementManifests> <ElementManifest Location="Elements.xml" /> </ElementManifests></Feature> Case 1: <Elements xmlns="http://schemas.microsoft.com/sharepoint/"> <CustomAction Id="EditMenu1" RegistrationType="FileType" RegistrationId="txt" Location="EditControlBlock" Sequence="106" ImageUrl="/_layouts/images/PPT16.GIF" Title="My Edit Menu" Rights="AddListItems,EditListItems"> <UrlAction Url="javascript:var surl='{SiteUrl}'; window.location='/test/mypage.aspx?siteurl='+surl+'&amp;itemurl={ItemUrl}&amp;itemid={ItemId}&amp;listid={ListId}&amp;Source='+window.location" /> </CustomAction> <CustomAction Id="NewMenu1" GroupId="NewMenu" RegistrationType="List" RegistrationId="101" Location="Microsoft.SharePoint.StandardMenu" Sequence="1002" ImageUrl ="/_layouts/images/DOC32.GIF" Title="My New Menu" Rights="AddListItems,EditListItems"> <UrlAction Url="javascript:var surl='{SiteUrl}'; window.location='/test/mypage.aspx?siteurl='+surl+'&amp;listid={ListId}&amp;Source='+window.location" /> </CustomAction> </Elements> If i use the above code, it was not redirected to site collection instead of it is redirecting to rootsite. Is there is any way to get the site collection variable. To overcome this issue i used the following code: Case 2: <?xml version="1.0" encoding="utf-8" ?> <Elements xmlns="http://schemas.microsoft.com/sharepoint/"> <CustomAction Id="EditMenu1" RegistrationType="FileType" RegistrationId="txt" Location="EditControlBlock" Sequence="106" ImageUrl="/_layouts/images/PPT16.GIF" Title="My Edit Menu" Rights="AddListItems,EditListItems"> <UrlAction Url="~sitecollection/test/mypage.aspx?siteurl={SiteUrl}&amp;itemurl={ItemUrl}&amp;itemid={ItemId}&amp;listid={ListId}&amp;Source=/" /> </CustomAction> <CustomAction Id="NewMenu1" GroupId="NewMenu" RegistrationType="List" RegistrationId="101" Location="Microsoft.SharePoint.StandardMenu" Sequence="1002" ImageUrl ="/_layouts/images/DOC32.GIF" Title="My New Menu" Rights="AddListItems,EditListItems"> <UrlAction Url="~sitecollection/test/mypage.aspx?siteurl={SiteUrl}&amp;listid={ListId}&amp;Source=/" /> </CustomAction> </Elements> But in this case, it is correctly redirected to the site collection. But it fails to get the folder url because current location can't pass through in this case. while creating new document. Could you please suggest me either how to get the site collection url in the case 1 or how to pass the current location to the sourceul in case 2

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  • Can't seem to redirect from a ViewScoped constructor.

    - by Andrew
    I'm having trouble redirecting from a view scoped bean in the case that we don't have the required info for the page in question. The log entry in the @PostContruct is visible in the log right before a NPE relating to the view trying to render itself instead of following my redirect. Why is it ignoring the redirect? Here's my code: @ManagedBean public class WelcomeView { private String sParam; private String aParam; public WelcomeView() { super(); sParam = getURL_Param("surveyName"); aParam = getURL_Param("accountName"); project = fetchProject(sParam, aParam); } @PostConstruct public void redirectWithoutProject() { if (null == project) { try { logger.warn("NO project [" + sParam + "] for account [" + aParam + "]"); FacesContext fc = FacesContext.getCurrentInstance(); fc.getExternalContext().redirect("/errors/noSurvey.jsf"); return; } catch (Exception e) { e.printStackTrace(); } } } .... public boolean getAuthenticated() { if (project.getPasswordProtected()) { return enteredPassword.equals(project.getLoginPassword()); } else return true; } } Here's the stack trace: SEVERE: Error Rendering View[/participant/welcome.xhtml] javax.el.ELException: /templates/participant/welcome.xhtml @80,70 rendered="#{welcomeView.authenticated}": Error reading 'authenticated' on type com.MYCODE.general.controllers.participant.WelcomeView at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:107) at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:190) at javax.faces.component.UIComponentBase.isRendered(UIComponentBase.java:416) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1607) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616) at javax.faces.render.Renderer.encodeChildren(Renderer.java:168) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:848) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1613) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616) at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:380) at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:126) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:127) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:313) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.MYCODE.general.filters.StatsFilter.doFilter(StatsFilter.java:28) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:568) at org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:421) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:637) Caused by: java.lang.NullPointerException at com.MYCODE.general.controllers.participant.WelcomeView$$M$863c205f.getAuthenticated(WelcomeView.java:127) at com.MYCODE.general.controllers.participant.WelcomeView$$A$863c205f.getAuthenticated(<generated>) at com.MYCODE.general.controllers.participant.WelcomeView.getAuthenticated(WelcomeView.java:125) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at javax.el.BeanELResolver.getValue(BeanELResolver.java:62) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:53) at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72) at org.apache.el.parser.AstValue.getValue(AstValue.java:118) at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186) at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:102) ... 33 more

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  • Reuse a facelet in multiple beans

    - by Seitaridis
    How do I invoke/access a property of a managed bean when the bean name is known, but is not yet constructed? For example: <p:selectOneMenu value="#{eval.evaluateAsBean(bean).text}" > <f:selectItems value="#{eval.evaluateAsBean(bean).values}" var="val" itemLabel="#{val}" itemValue="#{val}" /> </p:selectOneMenu> If there is a managed bean called testBean and in my view bean has the "testBean"value, I want the text or values property of testBean to be called. EDIT1 The context An object consists of a list of properties(values). One property is modified with a custom JSF editor, depending on its type. The list of editors is determined from the object's type, and displayed in a form using custom:include tags. This custom tag is used to dynamically include the editors <custom:include src="#{editor.component}">. The component property points to the location of the JSF editor. In my example some editors(rendered as select boxes) will use the same facelet(dynamicDropdown.xhtml). Every editor has a session scoped managed bean. I want to reuse the same facelet with multiple beans and to pass the name of the bean to dynamicDropdown.xhtml using the bean param. genericAccount.xhtml <p:dataTable value="#{group.editors}" var="editor"> <p:column headerText="Key"> <h:outputText value="#{editor.name}" /> </p:column> <p:column headerText="Value"> <h:panelGroup rendered="#{not editor.href}"> <h:outputText value="#{editor.component}" escape="false" /> </h:panelGroup> <h:panelGroup rendered="#{editor.href}"> <custom:include src="#{editor.component}"> <ui:param name="enabled" value="#{editor.enabled}"/> <ui:param name="bean" value="#{editor.bean}"/> <custom:include> </h:panelGroup> </p:column> </p:dataTable> #{editor.component} refers to a dynamicDropdown.xhtml file. dynamicDropdown.xhtml <ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:p="http://primefaces.prime.com.tr/ui"> <p:selectOneMenu value="#{eval.evaluateAsBean(bean).text}" > <f:selectItems value="#{eval.evaluateAsBean(bean).values}" var="val" itemLabel="#{val}" itemValue="#{val}" /> </p:selectOneMenu> </ui:composition> eval is a managed bean: @ManagedBean(name = "eval") @ApplicationScoped public class ELEvaluator { ... public Object evaluateAsBean(String el) { FacesContext context = FacesContext.getCurrentInstance(); Object bean = context.getELContext() .getELResolver().getValue(context.getELContext(), null, el); return bean; } ... }

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  • The best JSF coding pattern for editing JPA entities using @RequestScoped only

    - by AlanObject
    I am in a project where I will write a lot of pages like this, so I want to use the most efficient (to write) coding pattern. Background: In the past I have used CODI's @ViewAccessScoped to preserve state between requests, and more recently I have started using flash scoped objects to save state. I can't use JSF @ViewScoped because I use CDI and they don't play well together. So I want to see if I can do this with only @RequestScoped backing beans. The page is designed like this (the p namespace is Primefaces): <f:metadata> <f:viewParam name="ID" value="#{backing.id}" /> </f:metadata> .... <h1>Edit Object Page</h1> <h:form id="formObj" rendered="#{backing.accessOK}"> <p:panelGrid columns="2"> <h:outputLabel value="Field #1:"/> <p:inputText value="#{backing.record.field1}" /> (more input fields) <h:outputLabel value="Action:" /> <h:panelGroup> <p:commandButton value="Save" action="#{backing.save}" /> <p:commandButton value="Cancel" action="backing.cancel" /> </h:panelGroup> </p:panelGrid> <p:messages showDetail="true" showSummary="true" /> </h:form> If the page is requested, the method accessOK() has the ability to keep the h:form from being rendered. Instead, the p:messages is shown with whatever FacesMessage(s) the accessOK() method cares to set. The pattern for the bean backing looks like this: @Named @RequestScoped public class Backing { private long id; private SomeJPAEntity record; private Boolean accessOK; public long getId() { return id; } public void setId(long value) { id = value; } public boolean accessOK() { if (accessOK != null) return accessOK; if (getRecord() == null) { // add a FacesMessage that explains the record // does not exist return accessOK = false; // note single = } // do any other access checks, such as write permissions return accessOK = true; } public SomeJPAEntity getRecord() { if (record != null) return record; if (getId() > 0) record = // get the record from DB else record = new SomeJPAEntity(); return record; } public String execute() { if (!accessOK()) return null; // bad edit // do other integrity checks here. If fail, set FacesMessages // and return null; if (getId() > 0) // merge the record back into the data base else // persist the record } } Here is what goes wrong with this model. When the Save button is clicked, a new instance of Backing is built, and then there are a lot of calls to the getRecord() getter before the setID() setter is called. So the logic in getRecord() breaks because it cannot rely on the id property being valid when it is called. When this was a @ViewAccessScoped (or ViewScoped) backing bean, then both the id and record properties are already set when the form is processed with the commandButton. Alternatively you can save those properties in flash storage but that has its own problems I want to avoid. So is there a way to make this programming model work within the specification?

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  • How to reserve public API to internal usage in .NET?

    - by mark
    Dear ladies and sirs. Let me first present the case, which will explain my question. This is going to be a bit long, so I apologize in advance :-). I have objects and collections, which should support the Merge API (it is my custom API, the signature of which is immaterial for this question). This API must be internal, meaning only my framework should be allowed to invoke it. However, derived types should be able to override the basic implementation. The natural way to implement this pattern as I see it, is this: The Merge API is declared as part of some internal interface, let us say IMergeable. Because the interface is internal, derived types would not be able to implement it directly. Rather they must inherit it from a common base type. So, a common base type is introduced, which would implement the IMergeable interface explicitly, where the interface methods delegate to respective protected virtual methods, providing the default implementation. This way the API is only callable by my framework, but derived types may override the default implementation. The following code snippet demonstrates the concept: internal interface IMergeable { void Merge(object obj); } public class BaseFrameworkObject : IMergeable { protected virtual void Merge(object obj) { // The default implementation. } void IMergeable.Merge(object obj) { Merge(obj); } } public class SomeThirdPartyObject : BaseFrameworkObject { protected override void Merge(object obj) { // A derived type implementation. } } All is fine, provided a single common base type suffices, which is usually true for non collection types. The thing is that collections must be mergeable as well. Collections do not play nicely with the presented concept, because developers do not develop collections from the scratch. There are predefined implementations - observable, filtered, compound, read-only, remove-only, ordered, god-knows-what, ... They may be developed from scratch in-house, but once finished, they serve wide range of products and should never be tailored to some specific product. Which means, that either: they do not implement the IMergeable interface at all, because it is internal to some product the scope of the IMergeable interface is raised to public and the API becomes open and callable by all. Let us refer to these collections as standard collections. Anyway, the first option screws my framework, because now each possible standard collection type has to be paired with the respective framework version, augmenting the standard with the IMergeable interface implementation - this is so bad, I am not even considering it. The second option breaks the framework as well, because the IMergeable interface should be internal for a reason (whatever it is) and now this interface has to open to all. So what to do? My solution is this. make IMergeable public API, but add an extra parameter to the Merge method, I call it a security token. The interface implementation may check that the token references some internal object, which is never exposed to the outside. If this is the case, then the method was called from within the framework, otherwise - some outside API consumer attempted to invoke it and so the implementation can blow up with a SecurityException. Here is the modified code snippet demonstrating this concept: internal static class InternalApi { internal static readonly object Token = new object(); } public interface IMergeable { void Merge(object obj, object token); } public class BaseFrameworkObject : IMergeable { protected virtual void Merge(object obj) { // The default implementation. } public void Merge(object obj, object token) { if (!object.ReferenceEquals(token, InternalApi.Token)) { throw new SecurityException("bla bla bla"); } Merge(obj); } } public class SomeThirdPartyObject : BaseFrameworkObject { protected override void Merge(object obj) { // A derived type implementation. } } Of course, this is less explicit than having an internally scoped interface and the check is moved from the compile time to run time, yet this is the best I could come up with. Now, I have a gut feeling that there is a better way to solve the problem I have presented. I do not know, may be using some standard Code Access Security features? I have only vague understanding of it, but can LinkDemand attribute be somehow related to it? Anyway, I would like to hear other opinions. Thanks.

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  • CodePlex Daily Summary for Saturday, June 05, 2010

    CodePlex Daily Summary for Saturday, June 05, 2010New Projects555 Calculator: A simple calculator to help choosing resistor and capacitor values to get the frequency you're looking for on a 555 timer.BleQua .NET: PL: Program sieciowy BleQua .NET jest multi-komunikatorem. EN: Network program BleQua .NET is multicomunicator.ChatDiplomaWork: ChatSample is the sample project.CSUFVGDC Summer Jam: Repository for VGDC summer game jam.Database Export Wizard: ExportWizard is a Step Wizard for Database Export using ASP.net and SQL Server. It allows easy export in any of the standard formats: CSV, TXT, HTM...Dozer Enterprise Library for .NET: a light .net framework for enterprise applications developmentEmployee Management System: This is an Employee Management System. the goal here is to offer a software that caters to small to mid sized businesses for free. This program a...Fanray: My project on Codeplex.Infragistics Analytics Framework: This project includes wrappers for the Infragistics controls that integrate with the recently launched Microsoft Silverlight Analytics Framework. ...KIME Simio Extensions: This is the official project of KIME Solutions. Here you find any current developments of KIME that are publicly available. KIME develops extension...MindTouch Community Extensions: MindTouch Community Extentions is a Native C# extention library for MindTouch Core that will have Dekiscript functions for full coverage of the API...NginxTray: NginxTray allows you manage easily Nginx Web Server by a Tray icon.NStore: NStore is a virtual store example done with ASP.NET MVC 2.0 tecnologyProjet Campus Numerique + Appli Mobile: Projet de création d'un campus numérique pour l'ISEN et d'un application mobile d'accès.SharePoint 2010 Feature Upgrade Kit: A set of tools for managing upgradable Features in SharePoint 2010. (Upgrading Features is a means of deploying code/artifact updates to existing S...SiteMap Utility for DNN Blog Module: This is a mini-project which allows you to easily add or generate an XML site map to your DotNetNuke® website for the search engines to use to inde...Space Explorer: A small app to help users examine folders to see which files and subfolders are taking up space. Still in development, no releases available curren...SQL Compact Toolbox: SQL Compact Toolbox is a Visual Studio 2010 add-in, that adds scripting, import, export, migrate, rename, run script and other upcoming SQL Server ...Twilverlight: Twliverlight is TweetDeck mixed with Silverlight. Much as I like using TweetDeck, it hogs my memory out, so this is an attempt to write a memory-ef...Visual Studio 2010 FxCop Extension: Visual Studio 2010 FxCop Extension allows to integrate stand-alone FxCop into Visual Studio 2010. You'll be able to analysis your source code with ...VisualStudio 2010 JavaScript Outlining: Visual Studio 2010 editor extension for JavaScript code blocks and custom regions outlining Wiki Shelf: Wiki Shelf is a Wikipedia browser app. The goal is to bring the library experience of browsing books, studying, and researching to the Wikipedia u...X-Arena - Magic: Projeto de PDS2 no Curso de Tecnologia em Desenvolvimento de Software no CEFETRN. O desenvolvimento do jogo Quiz Arena possui como pr...New Releases555 Calculator: 555Calc release v1.0: The initial 1 point uh-oh release of 555Calc.BleQua .NET: BleQua .NET 1.0.0.0: First releaseChatterbot JBot: JBot 1.0.1.155: Change presentation technology from Window Forms to Widndown Presentation Fundation.Community Forums NNTP bridge: Community Forums NNTP Bridge V26: Release of the Community Forums NNTP Bridge to access the social and anwsers MS forums with a single, open source NNTP bridge. This release has ad...Community Forums NNTP bridge: Community Forums NNTP Bridge V27: Release of the Community Forums NNTP Bridge to access the social and anwsers MS forums with a single, open source NNTP bridge. This release has ad...Community Forums NNTP bridge: Community Forums NNTP Bridge V28: Release of the Community Forums NNTP Bridge to access the social and anwsers MS forums with a single, open source NNTP bridge. This release has ad...CSS 360 Planetary Calendar: Final Release: =============================================================================== Final Release Version: 2.0 Tools Used: - Collaboration, Releas...Database Export Wizard: Version 3: As described in CodeProject article: Database Export Wizard for ASP.net and SQL Server. http://www.codeproject.com/KB/aspnet/DatabaseExportWizard.aspxEdu Math: Edu Math 2.0.10.122: Change version .NET Framework.Employee Management System: V1 (beta): This version is still in beta testing. Any issues, comments or suggestions are greatly appreciated. The export to excel function in this release o...ESB.NET: ESBDeploy_7.0.27.0 (x64 and x86) [ESB.NET 7.0 RC1]: Release Details Changes Since Last Release (since 6.3.47.1) - Targets .NET Framework 4, Visual Studio.NET 2010, Workflow 4 - Flowchart workflow ada...Free Silverlight & WPF Chart Control - Visifire: Visifire SL and WPF Charts v3.1.1 beta 2 Released: Hi, This release contains the following enhancements: *ShowIndicator() and HideIndicator() function has been implemented in Chart. So now user wi...Free Silverlight & WPF Chart Control - Visifire: Visifire SL and WPF Charts v3.5.4 beta 2 Released: Hi, This release contains the following enhancements: *ShowIndicator() and HideIndicator() function has been implemented in Chart. So now user wi...FsCheck: A random testing framework: FsCheck 0.7: What to download? If you use F# April 2010 CTP with Visual Studio 2008 or Visual Studio 2010, either Source or Binaries will do. To open source in...Git Source Control Provider: V 0.5: For VS 2010 users, it is recommanded to install it within Visual Studio by selecting Tools | Extension Manager. Run Visual Studio. Go to Tools ...GPdotNET - Genetic Programming Tool: GPdotNETv0.95: 1. Localization support 2. Export functionality for GP Model with training and testing data. 3. Export GPModel with Testing and Training data. 4....JoshDOS: JoshDOS 1.1: 1.1 adds a toutorial of how to create new commands and of course, you need the COMSOS user kit or dev kit. Ver 1.1 also includes a demo called Gue...KIME Simio Extensions: KIME.SimioDebugStep: This simple Simio step allows you to debug any number of expressions from within the simulation run. The debug information is displayed using a mes...NginxTray: NginxTray 0.3 Beta 2: NginxTray 0.3 Beta 2NginxTray: NginxTray 0.5 Beta 3: NginxTray 0.5 Beta 3NginxTray: NginxTray 0.6 RC1: NginxTray 0.6 RC1Open Source PLM Activities: Prodeos_OC beta 1.0: The “Innovator – MS Office Connector” is a product developed by Prodeos (www.prodeos.com). It is a light connector made to facilitate the use of Mi...Paint.NET PSD Plugin: 1.5.1: Changes in this release: Bitmap-mode images can now be loaded. Thanks to dhnc for filing the bug. Plugin no longer crashes on files with user m...SharePoint 2010 Feature Upgrade Kit: 1.0.0.0: This release contains:- - Custom application page to manage the upgrade of Site and Web-scoped Features. To come in the next release: - Companio...SiteMap Utility for DNN Blog Module: Blog SiteMap Utility v01.00.01: This is the first public release of the SiteMap Utility for the core DotNetNuke® Blog Module. Please see the documentation on this site on how to...SqlDiffFramework-A Visual Differencing Engine for Dissimilar Data Sources: SqlDiffFramework 1.0.2.0: Maintenance Release Defect Fixes: Issue # 3: 3 Issue # 4: 4 Enhancements: About Box now displays regional and language settings in effect. SDF...SuperSocket: First release of SuperSocket: !First release of SuperSocketThe Fastcopy Helper: FastcopyHelper: Fastcopy Helper 2.0 This is a final one. You can use it on the way. In order to use it , you should have the .NET3.5 ! 此软件必须下载 .NET3.5平台,方可使用!TV Show Renamer: TV Show Renamer Beta 3: I found the bug the prevented it from closing correctly so I fixed it and had to release it right away. If anyone else finds any problems. contact me.UrzaGatherer: UrzaGatherer v2.0: UrzaGatherer is the first stable version. This release include UrzaBackgroundPictures.VisualStudio 2010 JavaScript Outlining: VisualStudion 2010 Javascript Outlining 1.0: Features Outlines JavaScript codeblock regions for the code placed between { }. Both places on a new line. Outlines custom regions defined by: //...Wouter's SharePoint Demo Land: Navigation Service with Proxy: A SharePoint 2010 Service Application that uses service proxies to relay commands to the actual service. The demo proxy makes use of in-memory comm...盘古分词-开源中文分词组件: V2.0.0.0: 进一步优化性能,分词速度达到将近 500K ,1.2.0.1 版本只有 320K 修改 PanGu.Lucene.Analyzer, 支持 Lucene.net 2.9 版本。 增加对字典中以数字开头的专业非中文词汇的识别 增加英文分词开关,权重由英文小写权重和英文词根权重两个参数来决定...Most Popular ProjectsCommunity Forums NNTP bridgeOutSyncASP.NET MVC Time PlannerNeatUploadMoonyDesk (windows desktop widgets)AgUnit - Silverlight unit testing with ReSharperViperWorks IgnitionASP.NET MVC ExtensionsAviva Solutions C# Coding GuidelinesMute4Most Active ProjectsCommunity Forums NNTP bridgeRawrpatterns & practices – Enterprise LibraryIonics Isapi Rewrite FilterGMap.NET - Great Maps for Windows Forms & PresentationN2 CMSStyleCopFarseer Physics Enginesmark C# LibraryMirror Testing System

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  • Table Variables: an empirical approach.

    - by Phil Factor
    It isn’t entirely a pleasant experience to publish an article only to have it described on Twitter as ‘Horrible’, and to have it criticized on the MVP forum. When this happened to me in the aftermath of publishing my article on Temporary tables recently, I was taken aback, because these critics were experts whose views I respect. What was my crime? It was, I think, to suggest that, despite the obvious quirks, it was best to use Table Variables as a first choice, and to use local Temporary Tables if you hit problems due to these quirks, or if you were doing complex joins using a large number of rows. What are these quirks? Well, table variables have advantages if they are used sensibly, but this requires some awareness by the developer about the potential hazards and how to avoid them. You can be hit by a badly-performing join involving a table variable. Table Variables are a compromise, and this compromise doesn’t always work out well. Explicit indexes aren’t allowed on Table Variables, so one cannot use covering indexes or non-unique indexes. The query optimizer has to make assumptions about the data rather than using column distribution statistics when a table variable is involved in a join, because there aren’t any column-based distribution statistics on a table variable. It assumes a reasonably even distribution of data, and is likely to have little idea of the number of rows in the table variables that are involved in queries. However complex the heuristics that are used might be in determining the best way of executing a SQL query, and they most certainly are, the Query Optimizer is likely to fail occasionally with table variables, under certain circumstances, and produce a Query Execution Plan that is frightful. The experienced developer or DBA will be on the lookout for this sort of problem. In this blog, I’ll be expanding on some of the tests I used when writing my article to illustrate the quirks, and include a subsequent example supplied by Kevin Boles. A simplified example. We’ll start out by illustrating a simple example that shows some of these characteristics. We’ll create two tables filled with random numbers and then see how many matches we get between the two tables. We’ll forget indexes altogether for this example, and use heaps. We’ll try the same Join with two table variables, two table variables with OPTION (RECOMPILE) in the JOIN clause, and with two temporary tables. It is all a bit jerky because of the granularity of the timing that isn’t actually happening at the millisecond level (I used DATETIME). However, you’ll see that the table variable is outperforming the local temporary table up to 10,000 rows. Actually, even without a use of the OPTION (RECOMPILE) hint, it is doing well. What happens when your table size increases? The table variable is, from around 30,000 rows, locked into a very bad execution plan unless you use OPTION (RECOMPILE) to provide the Query Analyser with a decent estimation of the size of the table. However, if it has the OPTION (RECOMPILE), then it is smokin’. Well, up to 120,000 rows, at least. It is performing better than a Temporary table, and in a good linear fashion. What about mixed table joins, where you are joining a temporary table to a table variable? You’d probably expect that the query analyzer would throw up its hands and produce a bad execution plan as if it were a table variable. After all, it knows nothing about the statistics in one of the tables so how could it do any better? Well, it behaves as if it were doing a recompile. And an explicit recompile adds no value at all. (we just go up to 45000 rows since we know the bigger picture now)   Now, if you were new to this, you might be tempted to start drawing conclusions. Beware! We’re dealing with a very complex beast: the Query Optimizer. It can come up with surprises What if we change the query very slightly to insert the results into a Table Variable? We change nothing else and just measure the execution time of the statement as before. Suddenly, the table variable isn’t looking so much better, even taking into account the time involved in doing the table insert. OK, if you haven’t used OPTION (RECOMPILE) then you’re toast. Otherwise, there isn’t much in it between the Table variable and the temporary table. The table variable is faster up to 8000 rows and then not much in it up to 100,000 rows. Past the 8000 row mark, we’ve lost the advantage of the table variable’s speed. Any general rule you may be formulating has just gone for a walk. What we can conclude from this experiment is that if you join two table variables, and can’t use constraints, you’re going to need that Option (RECOMPILE) hint. Count Dracula and the Horror Join. These tables of integers provide a rather unreal example, so let’s try a rather different example, and get stuck into some implicit indexing, by using constraints. What unusual words are contained in the book ‘Dracula’ by Bram Stoker? Here we get a table of all the common words in the English language (60,387 of them) and put them in a table. We put them in a Table Variable with the word as a primary key, a Table Variable Heap and a Table Variable with a primary key. We then take all the distinct words used in the book ‘Dracula’ (7,558 of them). We then create a table variable and insert into it all those uncommon words that are in ‘Dracula’. i.e. all the words in Dracula that aren’t matched in the list of common words. To do this we use a left outer join, where the right-hand value is null. The results show a huge variation, between the sublime and the gorblimey. If both tables contain a Primary Key on the columns we join on, and both are Table Variables, it took 33 Ms. If one table contains a Primary Key, and the other is a heap, and both are Table Variables, it took 46 Ms. If both Table Variables use a unique constraint, then the query takes 36 Ms. If neither table contains a Primary Key and both are Table Variables, it took 116383 Ms. Yes, nearly two minutes!! If both tables contain a Primary Key, one is a Table Variables and the other is a temporary table, it took 113 Ms. If one table contains a Primary Key, and both are Temporary Tables, it took 56 Ms.If both tables are temporary tables and both have primary keys, it took 46 Ms. Here we see table variables which are joined on their primary key again enjoying a  slight performance advantage over temporary tables. Where both tables are table variables and both are heaps, the query suddenly takes nearly two minutes! So what if you have two heaps and you use option Recompile? If you take the rogue query and add the hint, then suddenly, the query drops its time down to 76 Ms. If you add unique indexes, then you've done even better, down to half that time. Here are the text execution plans.So where have we got to? Without drilling down into the minutiae of the execution plans we can begin to create a hypothesis. If you are using table variables, and your tables are relatively small, they are faster than temporary tables, but as the number of rows increases you need to do one of two things: either you need to have a primary key on the column you are using to join on, or else you need to use option (RECOMPILE) If you try to execute a query that is a join, and both tables are table variable heaps, you are asking for trouble, well- slow queries, unless you give the table hint once the number of rows has risen past a point (30,000 in our first example, but this varies considerably according to context). Kevin’s Skew In describing the table-size, I used the term ‘relatively small’. Kevin Boles produced an interesting case where a single-row table variable produces a very poor execution plan when joined to a very, very skewed table. In the original, pasted into my article as a comment, a column consisted of 100000 rows in which the key column was one number (1) . To this was added eight rows with sequential numbers up to 9. When this was joined to a single-tow Table Variable with a key of 2 it produced a bad plan. This problem is unlikely to occur in real usage, and the Query Optimiser team probably never set up a test for it. Actually, the skew can be slightly less extreme than Kevin made it. The following test showed that once the table had 54 sequential rows in the table, then it adopted exactly the same execution plan as for the temporary table and then all was well. Undeniably, real data does occasionally cause problems to the performance of joins in Table Variables due to the extreme skew of the distribution. We've all experienced Perfectly Poisonous Table Variables in real live data. As in Kevin’s example, indexes merely make matters worse, and the OPTION (RECOMPILE) trick does nothing to help. In this case, there is no option but to use a temporary table. However, one has to note that once the slight de-skew had taken place, then the plans were identical across a huge range. Conclusions Where you need to hold intermediate results as part of a process, Table Variables offer a good alternative to temporary tables when used wisely. They can perform faster than a temporary table when the number of rows is not great. For some processing with huge tables, they can perform well when only a clustered index is required, and when the nature of the processing makes an index seek very effective. Table Variables are scoped to the batch or procedure and are unlikely to hang about in the TempDB when they are no longer required. They require no explicit cleanup. Where the number of rows in the table is moderate, you can even use them in joins as ‘Heaps’, unindexed. Beware, however, since, as the number of rows increase, joins on Table Variable heaps can easily become saddled by very poor execution plans, and this must be cured either by adding constraints (UNIQUE or PRIMARY KEY) or by adding the OPTION (RECOMPILE) hint if this is impossible. Occasionally, the way that the data is distributed prevents the efficient use of Table Variables, and this will require using a temporary table instead. Tables Variables require some awareness by the developer about the potential hazards and how to avoid them. If you are not prepared to do any performance monitoring of your code or fine-tuning, and just want to pummel out stuff that ‘just runs’ without considering namby-pamby stuff such as indexes, then stick to Temporary tables. If you are likely to slosh about large numbers of rows in temporary tables without considering the niceties of processing just what is required and no more, then temporary tables provide a safer and less fragile means-to-an-end for you.

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  • The Execute SQL Task

    In this article we are going to take you through the Execute SQL Task in SQL Server Integration Services for SQL Server 2005 (although it appies just as well to SQL Server 2008).  We will be covering all the essentials that you will need to know to effectively use this task and make it as flexible as possible. The things we will be looking at are as follows: A tour of the Task. The properties of the Task. After looking at these introductory topics we will then get into some examples. The examples will show different types of usage for the task: Returning a single value from a SQL query with two input parameters. Returning a rowset from a SQL query. Executing a stored procedure and retrieveing a rowset, a return value, an output parameter value and passing in an input parameter. Passing in the SQL Statement from a variable. Passing in the SQL Statement from a file. Tour Of The Task Before we can start to use the Execute SQL Task in our packages we are going to need to locate it in the toolbox. Let's do that now. Whilst in the Control Flow section of the package expand your toolbox and locate the Execute SQL Task. Below is how we found ours. Now drag the task onto the designer. As you can see from the following image we have a validation error appear telling us that no connection manager has been assigned to the task. This can be easily remedied by creating a connection manager. There are certain types of connection manager that are compatable with this task so we cannot just create any connection manager and these are detailed in a few graphics time. Double click on the task itself to take a look at the custom user interface provided to us for this task. The task will open on the general tab as shown below. Take a bit of time to have a look around here as throughout this article we will be revisting this page many times. Whilst on the general tab, drop down the combobox next to the ConnectionType property. In here you will see the types of connection manager which this task will accept. As with SQL Server 2000 DTS, SSIS allows you to output values from this task in a number of formats. Have a look at the combobox next to the Resultset property. The major difference here is the ability to output into XML. If you drop down the combobox next to the SQLSourceType property you will see the ways in which you can pass a SQL Statement into the task itself. We will have examples of each of these later on but certainly when we saw these for the first time we were very excited. Next to the SQLStatement property if you click in the empty box next to it you will see ellipses appear. Click on them and you will see the very basic query editor that becomes available to you. Alternatively after you have specified a connection manager for the task you can click on the Build Query button to bring up a completely different query editor. This is slightly inconsistent. Once you've finished looking around the general tab, move on to the next tab which is the parameter mapping tab. We shall, again, be visiting this tab throughout the article but to give you an initial heads up this is where you define the input, output and return values from your task. Note this is not where you specify the resultset. If however you now move on to the ResultSet tab this is where you define what variable will receive the output from your SQL Statement in whatever form that is. Property Expressions are one of the most amazing things to happen in SSIS and they will not be covered here as they deserve a whole article to themselves. Watch out for this as their usefulness will astound you. For a more detailed discussion of what should be the parameter markers in the SQL Statements on the General tab and how to map them to variables on the Parameter Mapping tab see Working with Parameters and Return Codes in the Execute SQL Task. Task Properties There are two places where you can specify the properties for your task. One is in the task UI itself and the other is in the property pane which will appear if you right click on your task and select Properties from the context menu. We will be doing plenty of property setting in the UI later so let's take a moment to have a look at the property pane. Below is a graphic showing our properties pane. Now we shall take you through all the properties and tell you exactly what they mean. A lot of these properties you will see across all tasks as well as the package because of everything's base structure The Container. BypassPrepare Should the statement be prepared before sending to the connection manager destination (True/False) Connection This is simply the name of the connection manager that the task will use. We can get this from the connection manager tray at the bottom of the package. DelayValidation Really interesting property and it tells the task to not validate until it actually executes. A usage for this may be that you are operating on table yet to be created but at runtime you know the table will be there. Description Very simply the description of your Task. Disable Should the task be enabled or not? You can also set this through a context menu by right clicking on the task itself. DisableEventHandlers As a result of events that happen in the task, should the event handlers for the container fire? ExecValueVariable The variable assigned here will get or set the execution value of the task. Expressions Expressions as we mentioned earlier are a really powerful tool in SSIS and this graphic below shows us a small peek of what you can do. We select a property on the left and assign an expression to the value of that property on the right causing the value to be dynamically changed at runtime. One of the most obvious uses of this is that the property value can be built dynamically from within the package allowing you a great deal of flexibility FailPackageOnFailure If this task fails does the package? FailParentOnFailure If this task fails does the parent container? A task can he hosted inside another container i.e. the For Each Loop Container and this would then be the parent. ForcedExecutionValue This property allows you to hard code an execution value for the task. ForcedExecutionValueType What is the datatype of the ForcedExecutionValue? ForceExecutionResult Force the task to return a certain execution result. This could then be used by the workflow constraints. Possible values are None, Success, Failure and Completion. ForceExecutionValue Should we force the execution result? IsolationLevel This is the transaction isolation level of the task. IsStoredProcedure Certain optimisations are made by the task if it knows that the query is a Stored Procedure invocation. The docs say this will always be false unless the connection is an ADO connection. LocaleID Gets or sets the LocaleID of the container. LoggingMode Should we log for this container and what settings should we use? The value choices are UseParentSetting, Enabled and Disabled. MaximumErrorCount How many times can the task fail before we call it a day? Name Very simply the name of the task. ResultSetType How do you want the results of your query returned? The choices are ResultSetType_None, ResultSetType_SingleRow, ResultSetType_Rowset and ResultSetType_XML. SqlStatementSource Your Query/SQL Statement. SqlStatementSourceType The method of specifying the query. Your choices here are DirectInput, FileConnection and Variables TimeOut How long should the task wait to receive results? TransactionOption How should the task handle being asked to join a transaction? Usage Examples As we move through the examples we will only cover in them what we think you must know and what we think you should see. This means that some of the more elementary steps like setting up variables will be covered in the early examples but skipped and simply referred to in later ones. All these examples used the AventureWorks database that comes with SQL Server 2005. Returning a Single Value, Passing in Two Input Parameters So the first thing we are going to do is add some variables to our package. The graphic below shows us those variables having been defined. Here the CountOfEmployees variable will be used as the output from the query and EndDate and StartDate will be used as input parameters. As you can see all these variables have been scoped to the package. Scoping allows us to have domains for variables. Each container has a scope and remember a package is a container as well. Variable values of the parent container can be seen in child containers but cannot be passed back up to the parent from a child. Our following graphic has had a number of changes made. The first of those changes is that we have created and assigned an OLEDB connection manager to this Task ExecuteSQL Task Connection. The next thing is we have made sure that the SQLSourceType property is set to Direct Input as we will be writing in our statement ourselves. We have also specified that only a single row will be returned from this query. The expressions we typed in was: SELECT COUNT(*) AS CountOfEmployees FROM HumanResources.Employee WHERE (HireDate BETWEEN ? AND ?) Moving on now to the Parameter Mapping tab this is where we are going to tell the task about our input paramaters. We Add them to the window specifying their direction and datatype. A quick word here about the structure of the variable name. As you can see SSIS has preceeded the variable with the word user. This is a default namespace for variables but you can create your own. When defining your variables if you look at the variables window title bar you will see some icons. If you hover over the last one on the right you will see it says "Choose Variable Columns". If you click the button you will see a list of checkbox options and one of them is namespace. after checking this you will see now where you can define your own namespace. The next tab, result set, is where we need to get back the value(s) returned from our statement and assign to a variable which in our case is CountOfEmployees so we can use it later perhaps. Because we are only returning a single value then if you remember from earlier we are allowed to assign a name to the resultset but it must be the name of the column (or alias) from the query. A really cool feature of Business Intelligence Studio being hosted by Visual Studio is that we get breakpoint support for free. In our package we set a Breakpoint so we can break the package and have a look in a watch window at the variable values as they appear to our task and what the variable value of our resultset is after the task has done the assignment. Here's that window now. As you can see the count of employess that matched the data range was 2. Returning a Rowset In this example we are going to return a resultset back to a variable after the task has executed not just a single row single value. There are no input parameters required so the variables window is nice and straight forward. One variable of type object. Here is the statement that will form the soure for our Resultset. select p.ProductNumber, p.name, pc.Name as ProductCategoryNameFROM Production.ProductCategory pcJOIN Production.ProductSubCategory pscON pc.ProductCategoryID = psc.ProductCategoryIDJOIN Production.Product pON psc.ProductSubCategoryID = p.ProductSubCategoryID We need to make sure that we have selected Full result set as the ResultSet as shown below on the task's General tab. Because there are no input parameters we can skip the parameter mapping tab and move straight to the Result Set tab. Here we need to Add our variable defined earlier and map it to the result name of 0 (remember we covered this earlier) Once we run the task we can again set a breakpoint and have a look at the values coming back from the task. In the following graphic you can see the result set returned to us as a COM object. We can do some pretty interesting things with this COM object and in later articles that is exactly what we shall be doing. Return Values, Input/Output Parameters and Returning a Rowset from a Stored Procedure This example is pretty much going to give us a taste of everything. We have already covered in the previous example how to specify the ResultSet to be a Full result set so we will not cover it again here. For this example we are going to need 4 variables. One for the return value, one for the input parameter, one for the output parameter and one for the result set. Here is the statement we want to execute. Note how much cleaner it is than if you wanted to do it using the current version of DTS. In the Parameter Mapping tab we are going to Add our variables and specify their direction and datatypes. In the Result Set tab we can now map our final variable to the rowset returned from the stored procedure. It really is as simple as that and we were amazed at how much easier it is than in DTS 2000. Passing in the SQL Statement from a Variable SSIS as we have mentioned is hugely more flexible than its predecessor and one of the things you will notice when moving around the tasks and the adapters is that a lot of them accept a variable as an input for something they need. The ExecuteSQL task is no different. It will allow us to pass in a string variable as the SQL Statement. This variable value could have been set earlier on from inside the package or it could have been populated from outside using a configuration. The ResultSet property is set to single row and we'll show you why in a second when we look at the variables. Note also the SQLSourceType property. Here's the General Tab again. Looking at the variable we have in this package you can see we have only two. One for the return value from the statement and one which is obviously for the statement itself. Again we need to map the Result name to our variable and this can be a named Result Name (The column name or alias returned by the query) and not 0. The expected result into our variable should be the amount of rows in the Person.Contact table and if we look in the watch window we see that it is.   Passing in the SQL Statement from a File The final example we are going to show is a really interesting one. We are going to pass in the SQL statement to the task by using a file connection manager. The file itself contains the statement to run. The first thing we are going to need to do is create our file connection mananger to point to our file. Click in the connections tray at the bottom of the designer, right click and choose "New File Connection" As you can see in the graphic below we have chosen to use an existing file and have passed in the name as well. Have a look around at the other "Usage Type" values available whilst you are here. Having set that up we can now see in the connection manager tray our file connection manager sitting alongside our OLE-DB connection we have been using for the rest of these examples. Now we can go back to the familiar General Tab to set up how the task will accept our file connection as the source. All the other properties in this task are set up exactly as we have been doing for other examples depending on the options chosen so we will not cover them again here.   We hope you will agree that the Execute SQL Task has changed considerably in this release from its DTS predecessor. It has a lot of options available but once you have configured it a few times you get to learn what needs to go where. We hope you have found this article useful.

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  • How to set up spf records to send mail from google hosted apps to gmail addresses

    - by Chris Adams
    Hi there, I'm trying to work out why email I send from one domain I own is rejected by another that I own, and while I think it may be related to how I've setup spf records, I'm not sure what steps I need to take to fix it. Here's the error message I receive: Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550-Verification failed for <[email protected]> 550-No Such User Here 550 Sender verify failed (state 14). Here's the response from [email protected] Delivered-To: [email protected] Received: by 10.86.92.9 with SMTP id p9cs85371fgb; Wed, 2 Sep 2009 22:33:32 -0700 (PDT) Received: by 10.90.205.4 with SMTP id c4mr2406190agg.29.1251956007562; Wed, 02 Sep 2009 22:33:27 -0700 (PDT) Return-Path: <[email protected]> Received: from verifier.port25.com (207-36-201-235.ptr.primarydns.com [207.36.201.235]) by mx.google.com with ESMTP id 26si831174aga.24.2009.09.02.22.33.25; Wed, 02 Sep 2009 22:33:26 -0700 (PDT) Received-SPF: pass (google.com: domain of [email protected] designates 207.36.201.235 as permitted sender) client-ip=207.36.201.235; Authentication-Results: mx.google.com; spf=pass (google.com: domain of [email protected] designates 207.36.201.235 as permitted sender) [email protected]; dkim=pass [email protected] DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=auth; d=port25.com; h=Date:From:To:Subject:Message-Id:In-Reply-To; [email protected]; bh=GRMrcnoucTl4upzqJYTG5sOZMLU=; b=uk6TjADEyZVRkceQGjH94ZzfVeRTsiZPzbXuhlqDt1m+kh1zmdUEoiTOzd89ryCHMbVcnG1JajBj 5vOMKYtA3g== DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=auth; d=port25.com; b=NqKCPK00Xt49lbeO009xy4ZRgMGpghvcgfhjNy7+qI89XKTzi6IUW0hYqCQyHkd2p5a1Zjez2ZMC l0u9CpZD3Q==; Received: from verifier.port25.com (127.0.0.1) by verifier.port25.com (PowerMTA(TM) v3.6a1) id hjt9pq0hse8u for <[email protected]>; Thu, 3 Sep 2009 01:26:52 -0400 (envelope-from <[email protected]>) Date: Thu, 3 Sep 2009 01:26:52 -0400 From: [email protected] To: [email protected] Subject: Authentication Report Message-Id: <[email protected]> Precedence: junk (auto_reply) In-Reply-To: <[email protected]> This message is an automatic response from Port25's authentication verifier service at verifier.port25.com. The service allows email senders to perform a simple check of various sender authentication mechanisms. It is provided free of charge, in the hope that it is useful to the email community. While it is not officially supported, we welcome any feedback you may have at <[email protected]>. Thank you for using the verifier, The Port25 Solutions, Inc. team ========================================================== Summary of Results ========================================================== SPF check: pass DomainKeys check: neutral DKIM check: neutral Sender-ID check: pass SpamAssassin check: ham ========================================================== Details: ========================================================== HELO hostname: fg-out-1718.google.com Source IP: 72.14.220.158 mail-from: [email protected] ---------------------------------------------------------- SPF check details: ---------------------------------------------------------- Result: pass ID(s) verified: [email protected] DNS record(s): stemcel.co.uk. 14400 IN TXT "v=spf1 include:aspmx.googlemail.com ~all" aspmx.googlemail.com. 7200 IN TXT "v=spf1 redirect=_spf.google.com" _spf.google.com. 300 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ?all" ---------------------------------------------------------- DomainKeys check details: ---------------------------------------------------------- Result: neutral (message not signed) ID(s) verified: [email protected] DNS record(s): ---------------------------------------------------------- DKIM check details: ---------------------------------------------------------- Result: neutral (message not signed) ID(s) verified: NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25's PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM. ---------------------------------------------------------- Sender-ID check details: ---------------------------------------------------------- Result: pass ID(s) verified: [email protected] DNS record(s): stemcel.co.uk. 14400 IN TXT "v=spf1 include:aspmx.googlemail.com ~all" aspmx.googlemail.com. 7200 IN TXT "v=spf1 redirect=_spf.google.com" _spf.google.com. 300 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ?all" ---------------------------------------------------------- SpamAssassin check details: ---------------------------------------------------------- SpamAssassin v3.2.5 (2008-06-10) Result: ham (-2.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.0 HTML_MESSAGE BODY: HTML included in message I've registered the spf records for my domain, as advised here Both domains pass validate according to Kitterman's spf record testing tools, so I'm somewhat confused about this. I also have the catchall address set up on the stemcel.co.uk domain here, but I don't have one setup for chrisadams.me.uk. Instead, we have the following forwarders setup [email protected] to [email protected] [email protected] to [email protected] [email protected] to [email protected] [email protected] to [email protected] Any ideas how to get this working? I'm not sure what I should be looking for here.

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  • Down Tools Week Cometh: Kissing Goodbye to CVs/Resumes and Cover Letters

    - by Bart Read
    I haven't blogged about what I'm doing in my (not so new) temporary role as Red Gate's technical recruiter, mostly because it's been routine, business as usual stuff, and because I've been trying to understand the role by doing it. I think now though the time has come to get a little more radical, so I'm going to tell you why I want to largely eliminate CVs/resumes and cover letters from the application process for some of our technical roles, and why I think that might be a good thing for candidates (and for us). I have a terrible confession to make, or at least it's a terrible confession for a recruiter: I don't really like CV sifting, or reading cover letters, and, unless I've misread the mood around here, neither does anybody else. It's dull, it's time-consuming, and it's somewhat soul destroying because, when all is said and done, you're being paid to be incredibly judgemental about people based on relatively little information. I feel like I've dirtied myself by saying that - I mean, after all, it's a core part of my job - but it sucks, it really does. (And, of course, the truth is I'm still a software engineer at heart, and I'm always looking for ways to do things better.) On the flip side, I've never met anyone who likes writing their CV. It takes hours and hours of faffing around and massaging it into shape, and the whole process is beset by a gnawing anxiety, frustration, and insecurity. All you really want is a chance to demonstrate your skills - not just talk about them - and how do you do that in a CV or cover letter? Often the best candidates will include samples of their work (a portfolio, screenshots, links to websites, product downloads, etc.), but sometimes this isn't possible, or may not be appropriate, or you just don't think you're allowed because of what your school/university careers service has told you (more commonly an issue with grads, obviously). And what are we actually trying to find out about people with all of this? I think the common criteria are actually pretty basic: Smart Gets things done (thanks for these two Joel) Not an a55hole* (sorry, have to get around Simple Talk's swear filter - and thanks to Professor Robert I. Sutton for this one) *Of course, everyone has off days, and I don't honestly think we're too worried about somebody being a bit grumpy every now and again. We can do a bit better than this in the context of the roles I'm talking about: we can be more specific about what "gets things done" means, at least in part. For software engineers and interns, the non-exhaustive meaning of "gets things done" is: Excellent coder For test engineers, the non-exhaustive meaning of "gets things done" is: Good at finding problems in software Competent coder Team player, etc., to me, are covered by "not an a55hole". I don't expect people to be the life and soul of the party, or a wild extrovert - that's not what team player means, and it's not what "not an a55hole" means. Some of our best technical staff are quiet, introverted types, but they're still pleasant to work with. My problem is that I don't think the initial sift really helps us find out whether people are smart and get things done with any great efficacy. It's better than nothing, for sure, but it's not as good as it could be. It's also contentious, and potentially unfair/inequitable - if you want to get an idea of what I mean by this, check out the background information section at the bottom. Before I go any further, let's look at the Red Gate recruitment process for technical staff* as it stands now: (LOTS of) People apply for jobs. All these applications go through a brutal process of manual sifting, which eliminates between 75 and 90% of them, depending upon the role, and the time of year**. Depending upon the role, those who pass the sift will be sent an assessment or telescreened. For the purposes of this blog post I'm only interested in those that are sent some sort of programming assessment, or bug hunt. This means software engineers, test engineers, and software interns, which are the roles for which I receive the most applications. The telescreen tends to be reserved for project or product managers. Those that pass the assessment are invited in for first interview. This interview is mostly about assessing their technical skills***, although we're obviously on the look out for cultural fit red flags as well. If the first interview goes well we'll invite candidates back for a second interview. This is where team/cultural fit is really scoped out. We also use this interview to dive more deeply into certain areas of their skillset, and explore any concerns that may have come out of the first interview (these obviously won't have been serious or obvious enough to cause a rejection at that point, but are things we do need to look into before we'd consider making an offer). We might subsequently invite them in for lunch before we make them an offer. This tends to happen when we're recruiting somebody for a specific team and we'd like them to meet all the people they'll be working with directly. It's not an interview per se, but can prove pivotal if they don't gel with the team. Anyone who's made it this far will receive an offer from us. *We have a slightly quirky definition of "technical staff" as it relates to the technical recruiter role here. It includes software engineers, test engineers, software interns, user experience specialists, technical authors, project managers, product managers, and development managers, but does not include product support or information systems roles. **For example, the quality of graduate applicants overall noticeably drops as the academic year wears on, which is not to say that by now there aren't still stars in there, just that they're fewer and further between. ***Some organisations prefer to assess for team fit first, but I think assessing technical skills is a more effective initial filter - if they're the nicest person in the world, but can't cut a line of code they're not going to work out. Now, as I suggested in the title, Red Gate's Down Tools Week is upon us once again - next week in fact - and I had proposed as a project that we refactor and automate the first stage of marking our programming assessments. Marking assessments, and in fact organising the marking of them, is a somewhat time-consuming process, and we receive many assessment solutions that just don't make the cut, for whatever reason. Whilst I don't think it's possible to fully automate marking, I do think it ought to be possible to run a suite of automated tests over each candidate's solution to see whether or not it behaves correctly and, if it does, move on to a manual stage where we examine the code for structure, decomposition, style, readability, maintainability, etc. Obviously it's possible to use tools to generate potentially helpful metrics for some of these indices as well. This would obviously reduce the marking workload, and would provide candidates with quicker feedback about whether they've been successful - though I do wonder if waiting a tactful interval before sending a (nicely written) rejection might be wise. I duly scrawled out a picture of my ideal process, which looked like this: The problem is, as soon as I'd roughed it out, I realised that fundamentally it wasn't an ideal process at all, which explained the gnawing feeling of cognitive dissonance I'd been wrestling with all week, whilst I'd been trying to find time to do this. Here's what I mean. Automated assessment marking, and the associated infrastructure around that, makes it much easier for us to deal with large numbers of assessments. This means we can be much more permissive about who we send assessments out to or, in other words, we can give more candidates the opportunity to really demonstrate their skills to us. And this leads to a question: why not give everyone the opportunity to demonstrate their skills, to show that they're smart and can get things done? (Two or three of us even discussed this in the down tools week hustings earlier this week.) And isn't this a lot simpler than the alternative we'd been considering? (FYI, this was automated CV/cover letter sifting by some form of textual analysis to ideally eliminate the worst 50% or so of applications based on an analysis of the 20,000 or so historical applications we've received since 2007 - definitely not the basic keyword analysis beloved of recruitment agencies, since this would eliminate hardly anyone who was awful, but definitely would eliminate stellar Oxbridge candidates - #fail - or some nightmarishly complex Google-like system where we profile all our currently employees, only to realise that we're never going to get representative results because we don't have a statistically significant sample size in any given role - also #fail.) No, I think the new way is better. We let people self-select. We make them the masters (or mistresses) of their own destiny. We give applicants the power - we put their fate in their hands - by giving them the chance to demonstrate their skills, which is what they really want anyway, instead of requiring that they spend hours and hours creating a CV and cover letter that I'm going to evaluate for suitability, and make a value judgement about, in approximately 1 minute (give or take). It doesn't matter what university you attended, it doesn't matter if you had a bad year when you took your A-levels - here's your chance to shine, so take it and run with it. (As a side benefit, we cut the number of applications we have to sift by something like two thirds.) WIN! OK, yeah, sounds good, but will it actually work? That's an excellent question. My gut feeling is yes, and I'll justify why below (and hopefully have gone some way towards doing that above as well), but what I'm proposing here is really that we run an experiment for a period of time - probably a couple of months or so - and measure the outcomes we see: How many people apply? (Wouldn't be surprised or alarmed to see this cut by a factor of ten.) How many of them submit a good assessment? (More/less than at present?) How much overhead is there for us in dealing with these assessments compared to now? What are the success and failure rates at each interview stage compared to now? How many people are we hiring at the end of it compared to now? I think it'll work because I hypothesize that, amongst other things: It self-selects for people who really want to work at Red Gate which, at the moment, is something I have to try and assess based on their CV and cover letter - but if you're not that bothered about working here, why would you complete the assessment? Candidates who would submit a shoddy application probably won't feel motivated to do the assessment. Candidates who would demonstrate good attention to detail in their CV/cover letter will demonstrate good attention to detail in the assessment. In general, only the better candidates will complete and submit the assessment. Marking assessments is much less work so we'll be able to deal with any increase that we see (hopefully we will see). There are obviously other questions as well: Is plagiarism going to be a problem? Is there any way we can detect/discourage potential plagiarism? How do we assess candidates' education and experience? What about their ability to communicate in writing? Do we still want them to submit a CV afterwards if they pass assessment? Do we want to offer them the opportunity to tell us a bit about why they'd like the job when they submit their assessment? How does this affect our relationship with recruitment agencies we might use to hire for these roles? So, what's the objective for next week's Down Tools Week? Pretty simple really - we want to implement this process for the Graduate Software Engineer and Software Engineer positions that you can find on our website. I will be joined by a crack team of our best developers (Kevin Boyle, and new Red-Gater, Sam Blackburn), and recruiting hostess with the mostest Laura McQuillen, and hopefully a couple of others as well - if I can successfully twist more arms before Monday.* Hopefully by next Friday our experiment will be up and running, and we may have changed the way Red Gate recruits software engineers for good! Stay tuned and we'll let you know how it goes! *I'm going to play dirty by offering them beer and chocolate during meetings. Some background information: how agonising over the initial CV/cover letter sift helped lead us to bin it off entirely The other day I was agonising about the new university/good degree grade versus poor A-level results issue, and decided to canvas for other opinions to see if there was something I could do that was fairer than my current approach, which is almost always to reject. This generated quite an involved discussion on our Yammer site: I'm sure you can glean a pretty good impression of my own educational prejudices from that discussion as well, although I'm very open to changing my opinion - hopefully you've already figured that out from reading the rest of this post. Hopefully you can also trace a logical path from agonising about sifting to, "Uh, hang on, why on earth are we doing this anyway?!?" Technorati Tags: recruitment,hr,developers,testers,red gate,cv,resume,cover letter,assessment,sea change

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  • IPV6 causing issue with DNS

    - by Mike Wells
    I have set up an 'internal' DNS at my work, basically we have ourdomain.com that is for internet, email etc and I have created on one of our linux network servers (debian) a DNS using bind9 with the domain ourdomain.inc. So based on my files below and the symptoms I'm describing; what effect could IPV6 be having on my setup? What can I do to fix this? I assume it is not actually the IPV6 causing the issue, but rather something in my setup. These are the critical (I think) files I have modified: named.conf.local zone "ourdomain.inc" { type master; file "/etc/bind/zones/ourdomain.inc.db"; }; zone "201.168.192.in-addr.arpa" { type master; file "/etc/bind/zones/rev.201.168.192.in-addr.arpa"; }; named.conf.options options { directory "/var/cache/bind"; // If there is a firewall between you and nameservers you want // to talk to, you may need to fix the firewall to allow multiple // ports to talk. See http://www.kb.cert.org/vuls/id/800113 // If your ISP provided one or more IP addresses for stable // nameservers, you probably want to use them as forwarders. // Uncomment the following block, and insert the addresses replacing // the all-0's placeholder. forwarders { 1.2.3.4; //IP of our external DNS provider }; auth-nxdomain no; # conform to RFC1035 listen-on-v6 { any; }; }; ourdomain.inc.db $TTL 86400 ourdomain.inc. IN SOA ns1.ipower.com. admin.ourdomain.inc. ( 2006081401 28800 3600 604800 38400 ) serv1 IN A 192.168.201.223 serv2 IN A 192.168.201.220 serv3 IN A 192.168.201.219 ns1.ipower.com. IN A 1.2.3.4 ns2.ipower.com. IN A 1.2.3.5 @ IN NS ns1.ipower.com. @ IN NS ns2.ipower.com. svn IN CNAME serv1 docs IN CNAME serv2 jira IN CNAME serv3 confluence IN CNAME serv3 fisheye IN CNAME serv3 rev.201.168.192.in-addr.arpa $TTL 86400 201.168.192.in-addr.arpa. IN SOA ns1.ipower.com. admin.ourdomain.inc. ( 2006081401; 28800; 604800; 604800; 86400 ) 223 IN PTR serv1 @ IN NS ns1.ipower.com. @ IN NS ns2.ipower.com. named.conf include "/etc/bind/named.conf.options"; include "/etc/bind/named.conf.local"; include "/etc/bind/named.conf.default-zones"; I then made our internal DNS my preferred DNS with the two external DNSs the next in-line. More the most part this seems to work, I can ping svn.ourdomain.inc and it resolves to the correct IP, I can also ping google.com and it also resolves no problem. So all seem good. However, periodically (couple of times a day at least), I loose the ability to ping the svn.domain.inc (and all others defined under the internal DNS). What seem to fix the issue temporarily is to disable IPV6 on the network adapter of the client machine and then re-enable it. Then it works for a bit but will always fail again. System Info Internal DNS Distributor ID: Debian Description: Debian GNU/Linux 6.0.6 (squeeze) Release: 6.0.6 Codename: squeeze Linux 2.6.32-5-686 i686 BIND 9.7.3 PC OS Name: Microsoft Windows 7 Professional OS Version: 6.1.7601 Service Pack 1 Build 7601 System Type: x64-based PC Network Card(s): 2 NIC(s) Installed. [01]: Realtek PCIe GBE Family Controller Connection Name: WORK LAN DHCP Enabled: No IP address(es) [01]: the.ipv4.address [02]: the:ipv6:address The question... So based on my files above and the symptoms I described; what effect could IPV6 be having on my setup? What can I do to fix this? I assume it is not actually the IPV6 causing the issue, but rather something in my setup.

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  • Random Access Violation Exception in WPF Application

    - by PT1984
    Hi, I am facing weird problem while running regression tests on my WPF Application. I am getting AccessViolationException with different stacktraces each time. First : Message :Attempted to read or write protected memory. This is often an indication that other memory is corrupt. StackTrace : at MS.Win32.PresentationCore.UnsafeNativeMethods.MILUnknown.Release(IntPtr pIUnkown) at MS.Win32.PresentationCore.UnsafeNativeMethods.MILUnknown.ReleaseInterface(IntPtr& ptr) at System.Windows.Media.SafeMILHandle.ReleaseHandle() at System.Runtime.InteropServices.SafeHandle.InternalFinalize() at System.Runtime.InteropServices.SafeHandle.Dispose(Boolean disposing) at System.Runtime.InteropServices.SafeHandle.Finalize() Source :PresentationCore Type : System.AccessViolationException. Second : Message :Attempted to read or write protected memory. This is often an indication that other memory is corrupt. StackTrace : at MS.Win32.PresentationCore.UnsafeNativeMethods.IMILBitmapEffect.GetOutput(SafeHandle THIS_PTR, UInt32 uiIndex, SafeMILHandle pContext, BitmapSourceSafeMILHandle& ppBitmapSource) at System.Windows.Media.Effects.BitmapEffect.GetOutput(SafeHandle unmanagedEffect, Int32 index, BitmapEffectRenderContext context) at System.Windows.Media.Effects.BitmapEffect.GetOutput(BitmapEffectInput input) at System.Windows.Media.Effects.BitmapEffectState.GetEffectOutput(Visual visual, RenderTargetBitmap& renderBitmap, Matrix worldTransform, Rect windowClip, Matrix& finalTransform) at System.Windows.Media.Effects.BitmapEffectVisualState.RenderBitmapEffect(Visual visual, Channel channel) at System.Windows.Media.Effects.BitmapEffectContent.ExecuteRealizationsUpdate() at System.Windows.Media.RealizationContext.RealizationUpdateSchedule.Execute() at System.Windows.Media.MediaContext.Render(ICompositionTarget resizedCompositionTarget) at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) at System.Windows.Media.MediaContext.AnimatedRenderMessageHandler(Object resizedCompositionTarget) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter) at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at Main() Source :PresentationCore Type :System.AccessViolationException In Application Event Log I found following entries : Dispatcher processing has been suspended, but messages are still being processed. Faulting application **.exe, version 1.0.0.*, stamp 4c08d288, faulting module wpfgfx_v0300.dll, version 3.0.6920.1427, stamp 488f3056, debug? 0, fault address 0x0012ec36. My Application uses Dispatcher from another thread, to change the values of the controls , enable - disable those, change visibility etc., the thred is run multiple times in a second. Please let me know if anybody has faced this problem? Thanks in advance, -Prasad

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  • Access violation when accessing a COM object from .Net

    - by Groo
    Dear Sirs, I am sorry if the post is too long, but I would be happy if someone would at least point read the bolded titles, and point me in the right direction. I am having this problem for couple of days, but was unable to found the answer on the net. These are the things I have found out so far. 1. "Access violation" exception crushes my managed application My C# WinForms app sometimes closes with an "Access violation" exception ("Attempted to read or write protected memory"), right in the moment when selecting a TabPage in a windows form TabControl. From the stack trace (try/catch around Application.Run) I can see that the exception happens at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg), called inside UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData). -- Message: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. -- Stack trace: at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager .System.Windows.Forms.UnsafeNativeMethods .IMsoComponentManager.FPushMessageLoop (Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext .RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext .RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at MyApp.Program.Main() 2. The faulting module seems to be a COM object (ChartFX Client Server 6.2) Using WinDbg (with SoS loaded), I caught it on the unmanaged side, inside ChartFX.ClientServer.Core.dll (that's a COM charting component we are using): (ca84.c98c): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. eax=00000000 ebx=06e67c38 ecx=06e67c38 edx=000018c6 esi=06e7df30 edi=317a9e80 eip=31666110 esp=0015e040 ebp=0015e08c iopl=0 nv up ei pl zr na pe nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010246 ChartFX_ClientServer_Core!Ordinal5507+0x97b7: 31666110 8a404d mov al,byte ptr [eax+4Dh] ds:0023:0000004d=?? [edit:] I also wasn't able to get the unmamanged stack details from WinDbg (it said "Stack unwind info not available"): 0:000 kP ChildEBP RetAddr WARNING: Stack unwind information not available. Following frames may be wrong. 0015e08c 3166288b ChartFX_ClientServer_Core!Ordinal5507+0x97b7 0015e394 3165a921 ChartFX_ClientServer_Core!Ordinal5507+0x5f32 0015e480 31678685 ChartFX_ClientServer_Core!Ordinal5496+0x26a 0015e568 3167bef4 ChartFX_ClientServer_Core!Ordinal5492+0x975 0015e668 316a356b ChartFX_ClientServer_Core!Ordinal5492+0x41e4 0015e77c 31709496 ChartFX_ClientServer_Core!Ordinal443+0x5745 0015e7d0 31707f70 ChartFX_ClientServer_Core!Ordinal2584+0x3cdc 0015e7f8 3170817d ChartFX_ClientServer_Core!Ordinal2584+0x27b6 0015e81c 3162fd76 ChartFX_ClientServer_Core!Ordinal2584+0x29c3 0015e86c 7719f8d2 ChartFX_ClientServer_Core!Ordinal899+0x6b6 0015e898 7719f794 USER32!GetMessageW+0x93 0015e910 771a06f6 USER32!GetWindowLongW+0x115 0015e940 771a069c USER32!CallWindowProcW+0x75 0015e960 747fcef4 USER32!CallWindowProcW+0x1b 0015e97c 747fd073 comctl32!Ordinal377+0x5c 0015e9e0 747fd027 comctl32!DefSubclassProc+0x92 0015ea04 747fd4e6 comctl32!DefSubclassProc+0x46 0015ea20 747fd073 comctl32!DefSubclassProc+0x505 0015ea84 747fd118 comctl32!DefSubclassProc+0x92 0015eae4 7719f8d2 comctl32!DefSubclassProc+0x137 3. Bug is not easy to reproduce (although it can be provoked usually in less than 5 min.) I have several Chart instances in several TabPages, and this usually happens while I am switching the tabs. I still don't know how to reproduce it, besides switching those tabs for several minutes before it happens, so I cannot use our source control to reliably find the build which didn't have this problem. I am accessing the charts through the managed AxChart wrapper class (derived from AxHost), which was created by VS designer automatically. 4. What should be my next step? If someone could point me to the next step I should do to find the actual cause, I would be very grateful. Experimenting (removing and returning code) does not do much good, because I don't know how to reproduce it, so it would take large amounts of time on each iteration just to convince myself that the bug is still there. I have found that people often suggest something like "switching compiler optimizations", but since the exception is not thrown deterministically, I don't want to simply rearrange some bytes and hope that it never returns. Thanks a lot in advance! Best regards, Groo

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  • Can't access a map member from a pointer

    - by fjfnaranjo
    Hi. That's my first question :) I'm storing the configuration of my program in a Group->Key->Value form, like the old INIs. I'm storing the information in a pair of structures. First one, I'm using a std::map with string+ptr for the groups info (the group name in the string key). The second std::map value is a pointer to the sencond structure, a std::list of std::maps, with the finish Key->Value pairs. The Key-Value pairs structure is created dynamically, so the config structure is: std::map< std::string , std::list< std::map<std::string,std::string> >* > lv1; Well, I'm trying to implement two methods to check the existence of data in the internal config. The first one, check the existence of a group in the structure: bool isConfigLv1(std::string); bool ConfigManager::isConfigLv1(std::string s) { return !(lv1.find(s)==lv1.end()); } The second method, is making me crazy... It check the existence for a key inside a group. bool isConfigLv2(std::string,std::string); bool ConfigManager::isConfigLv2(std::string s,std::string d) { if(!isConfigLv1(s)) return false; std::map< std::string , std::list< std::map<std::string,std::string> >* >::iterator it; std::list< std::map<std::string,std::string> >* keyValue; std::list< std::map<std::string,std::string> >::iterator keyValueIt; it = lv1.find(s); keyValue = (*it).second; for ( keyValueIt = keyValue->begin() ; keyValueIt != keyValue->end() ; keyValueIt++ ) if(!((*keyValueIt).second.find(d)==(*keyValueIt).second.end())) return true; return false; } I don't understand what is wrong. The compiler says: ConfigManager.cpp||In member function ‘bool ConfigManager::isConfigLv2(std::string, std::string)’:| ConfigManager.cpp|(line over return true)|error: ‘class std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >’ has no member named ‘second’| But it has to have the second member, because it's a map iterator... Any suggestion about what's happening? Sorry for my English :P, and consider I'm doing it as a exercise, I know there are a lot of cool configuration managers.

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  • Dynamic scoping in Clojure?

    - by j-g-faustus
    Hi, I'm looking for an idiomatic way to get dynamically scoped variables in Clojure (or a similar effect) for use in templates and such. Here is an example problem using a lookup table to translate tag attributes from some non-HTML format to HTML, where the table needs access to a set of variables supplied from elsewhere: (def *attr-table* ; Key: [attr-key tag-name] or [boolean-function] ; Value: [attr-key attr-value] (empty array to ignore) ; Context: Variables "tagname", "akey", "aval" '( ; translate :LINK attribute in <a> to :href [:LINK "a"] [:href aval] ; translate :LINK attribute in <img> to :src [:LINK "img"] [:src aval] ; throw exception if :LINK attribute in any other tag [:LINK] (throw (RuntimeException. (str "No match for " tagname))) ; ... more rules ; ignore string keys, used for internal bookkeeping [(string? akey)] [] )) ; ignore I want to be able to evaluate the rules (left hand side) as well as the result (right hand side), and need some way to put the variables in scope at the location where the table is evaluated. I also want to keep the lookup and evaluation logic independent of any particular table or set of variables. I suppose there are similar issues involved in templates (for example for dynamic HTML), where you don't want to rewrite the template processing logic every time someone puts a new variable in a template. Here is one approach using global variables and bindings. I have included some logic for the table lookup: ;; Generic code, works with any table on the same format. (defn rule-match? [rule-val test-val] "true if a single rule matches a single argument value" (cond (not (coll? rule-val)) (= rule-val test-val) ; plain value (list? rule-val) (eval rule-val) ; function call :else false )) (defn rule-lookup [test-val rule-table] "looks up rule match for test-val. Returns result or nil." (loop [rules (partition 2 rule-table)] (when-not (empty? rules) (let [[select result] (first rules)] (if (every? #(boolean %) (map rule-match? select test-val)) (eval result) ; evaluate and return result (recur (rest rules)) ))))) ;; Code specific to *attr-table* (def tagname) ; need these globals for the binding in html-attr (def akey) (def aval) (defn html-attr [tagname h-attr] "converts to html attributes" (apply hash-map (flatten (map (fn [[k v :as kv]] (binding [tagname tagname akey k aval v] (or (rule-lookup [k tagname] *attr-table*) kv))) h-attr )))) (defn test-attr [] "test conversion" (prn "a" (html-attr "a" {:LINK "www.google.com" "internal" 42 :title "A link" })) (prn "img" (html-attr "img" {:LINK "logo.png" }))) user=> (test-attr) "a" {:href "www.google.com", :title "A link"} "img" {:src "logo.png"} This is nice in that the lookup logic is independent of the table, so it can be reused with other tables and different variables. (Plus of course that the general table approach is about a quarter of the size of the code I had when I did the translations "by hand" in a giant cond.) It is not so nice in that I need to declare every variable as a global for the binding to work. Here is another approach using a "semi-macro", a function with a syntax-quoted return value, that doesn't need globals: (defn attr-table [tagname akey aval] `( [:LINK "a"] [:href ~aval] [:LINK "img"] [:src ~aval] [:LINK] (throw (RuntimeException. (str "No match for " tagname))) ; ... more rules [(string? ~akey)] [] ))) Only a couple of changes are needed to the rest of the code: In rule-match?, when syntax-quoted the function call is no longer a list: - (list? rule-val) (eval rule-val) + (seq? rule-val) (eval rule-val) In html-attr: - (binding [tagname tagname akey k aval v] - (or (rule-lookup [k tagname] *attr-table*) kv))) + (or (rule-lookup [k tagname] (attr-table tagname k v)) kv))) And we get the same result without globals. (And without dynamic scoping.) Are there other alternatives to pass along sets of variable bindings declared elsewhere, without the globals required by Clojure's binding? Is there an idiomatic way of doing it, like Ruby's binding or Javascript's function.apply(context)?

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  • Counting leaf nodes in hierarchical tree

    - by timn
    This code fills a tree with values based their depths. But when traversing the tree, I cannot manage to determine the actual number of children. node-cnt is always 0. I've already tried node-parent-cnt but that gives me lots of warnings in Valgrind. Anyway, is the tree type I've chosen even appropriate for my purpose? #include <string.h> #include <stdio.h> #include <stdlib.h> #ifndef NULL #define NULL ((void *) 0) #endif // ---- typedef struct _Tree_Node { // data ptr void *p; // number of nodes int cnt; struct _Tree_Node *nodes; // parent nodes struct _Tree_Node *parent; } Tree_Node; typedef struct { Tree_Node root; } Tree; void Tree_Init(Tree *this) { this->root.p = NULL; this->root.cnt = 0; this->root.nodes = NULL; this->root.parent = NULL; } Tree_Node* Tree_AddNode(Tree_Node *node) { if (node->cnt == 0) { node->nodes = malloc(sizeof(Tree_Node)); } else { node->nodes = realloc( node->nodes, (node->cnt + 1) * sizeof(Tree_Node) ); } Tree_Node *res = &node->nodes[node->cnt]; res->p = NULL; res->cnt = 0; res->nodes = NULL; res->parent = node; node->cnt++; return res; } // ---- void handleNode(Tree_Node *node, int depth) { int j = depth; printf("\n"); while (j--) { printf(" "); } printf("depth=%d ", depth); if (node->p == NULL) { goto out; } printf("value=%s cnt=%d", node->p, node->cnt); out: for (int i = 0; i < node->cnt; i++) { handleNode(&node->nodes[i], depth + 1); } } Tree tree; int curdepth; Tree_Node *curnode; void add(int depth, char *s) { printf("%s: depth (%d) > curdepth (%d): %d\n", s, depth, curdepth, depth > curdepth); if (depth > curdepth) { curnode = Tree_AddNode(curnode); Tree_Node *node = Tree_AddNode(curnode); node->p = malloc(strlen(s)); memcpy(node->p, s, strlen(s)); curdepth++; } else { while (curdepth - depth > 0) { if (curnode->parent == NULL) { printf("Illegal nesting\n"); return; } curnode = curnode->parent; curdepth--; } Tree_Node *node = Tree_AddNode(curnode); node->p = malloc(strlen(s)); memcpy(node->p, s, strlen(s)); } } void main(void) { Tree_Init(&tree); curnode = &tree.root; curdepth = 0; add(0, "1"); add(1, "1.1"); add(2, "1.1.1"); add(3, "1.1.1.1"); add(4, "1.1.1.1.1"); add(2, "1.1.2"); add(0, "2"); handleNode(&tree.root, 0); }

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  • Still cant find a solution... about ajax call

    - by booota
    Okay I have this ajax call $('.updatecom .registercomplaint').click(function(){ updatecomplaints(); }); This calls the function updatecomplaints() function updatecomplaints() { var tno = $(".updatecom #tno").val(); var status = $(".updatecom #status").val(); if(status=='DONE') { $(".updatecom #con").val(''); } var tname = $(".updatecom #tname").val(); var rg11 = $(".updatecom #crg11").val(); var rg06 = $(".updatecom #crg06").val(); var tvpins = $(".updatecom #tvpins").val(); var jointer = $(".updatecom #jointer").val(); var cquantity = $(".updatecom #conqty").val(); var nooftv = $(".updatecom #tvno").val(); var misc = $(".updatecom #misc").val(); var tcomments = $(".updatecom #tcomments").val(); var con = $(".updatecom #con").val(); //alert(tno+status+tname+rg11+rg06+tvpins+jointer+cquantity+nooftv+misc+tcomments+con); $.ajax( { type: "POST", url: "up_functions.php", data: "ticket="+ tno +"& opt=upcom" +"& status="+ status +"& tname="+ tname +"& rg11="+ rg11 +"& rg06="+ rg06 +"& tvpins="+ tvpins +"& jointer="+ jointer +"& cquantity="+ cquantity +"& nooftv="+ nooftv +"& misc="+ misc +"& tcomments="+ tcomments +"& con="+ con, success: function(response) { alert(response); } }); } here is my up_functions.php $tno = htmlspecialchars(trim($_REQUEST['ticket'])); $status = htmlspecialchars(trim($_REQUEST['status'])); $tname = htmlspecialchars(trim($_REQUEST['tname'])); $rg11 = htmlspecialchars(trim($_REQUEST['rg11'])); $rg06 = htmlspecialchars(trim($_REQUEST['rg06'])); $tvpins = htmlspecialchars(trim($_REQUEST['tvpins'])); $jointer = htmlspecialchars(trim($_REQUEST['jointer'])); $cquantity = htmlspecialchars(trim($_REQUEST['cquantity'])); $nooftv = htmlspecialchars(trim($_REQUEST['nooftv'])); $misc = htmlspecialchars(trim($_REQUEST['misc'])); $tcomments = htmlspecialchars(trim($_REQUEST['tcomments'])); $con = htmlspecialchars(trim($_REQUEST['con'])); $result=$ptr->upcomticketinfo($tno,$status,$tname,$rg11,$rg06,$tvpins,$jointer,$cquantity,$nooftv,$misc,$tcomments,$con); echo $result; and here is my upconticketinfo() php function function upcomticketinfo($tno,$status,$tname,$rg11,$rg06,$tvpins,$jointer,$cquantity,$nooftv,$misc,$tcomments,$con) { if($con!='' || $con!=NULL) { $this->query = "update `booking discription` set `STATUS`='$status',`CLOSED ON`='$con' where `TICKET NO`='$tno'"; $this->q_result = mysql_query($this->query,$this->conn) or die(mysql_error()); if($this->q_result) { $query = "update `tech detail` set `TECH NAME`='$tname',`CABLE RG11`='$rg11',`CABLE RG06`='$rg06',`TV PINS USED`='$tvpins',`JOINTER USED`='$jointer',`CONNECTOR QTY`='$cquantity',`NO OF TV`='$nooftv',`MISC`='$misc',`TECH COMMENTS`='$tcomments' where `BOOKING`='$tno'"; $q_result = mysql_query($query,$this->conn) or die(mysql_error()); if($q_result) { $response = "updated"; } else { $response = "error"; } } else { $response = "error"; } } else { $this->query = "update `booking discription` set `STATUS`='$status' where `TICKET NO`='$tno'"; $this->q_result = mysql_query($this->query,$this->conn) or die(mysql_error()); if($this->q_result) { $query = "update `tech detail` set `TECH NAME`='$tname',`CABLE RG11`='$rg11',`CABLE RG06`='$rg06',`TV PINS USED`='$tvpins',`JOINTER USED`='$jointer',`CONNECTOR QTY`='$cquantity',`NO OF TV`='$nooftv',`MISC`='$misc',`TECH COMMENTS`='$tcomments' where `BOOKING`='$tno'"; $q_result = mysql_query($query,$this->conn) or die(mysql_error()); if($q_result) { $response = "updated"; } else { $response = "error"; } } else { $response = "error"; } } return $response; } Question is that, this code is working just fine in IE8 i.e i am using... but it is not working in FF 3.6.3... I have checked each n everything... One thing is that the code works fine on FF too only when i debug the page with firebug debugger. Otherwise the alert in ajax success shows itself with nothing in it... Help me...

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  • Jquery ajax function working in IE but not in FF

    - by booota
    Okay I have this ajax call $('.updatecom .registercomplaint').click(function(){ updatecomplaints(); }); This calls the function updatecomplaints() function updatecomplaints() { var tno = $(".updatecom #tno").val(); var status = $(".updatecom #status").val(); if(status=='DONE') { $(".updatecom #con").val(''); } var tname = $(".updatecom #tname").val(); var rg11 = $(".updatecom #crg11").val(); var rg06 = $(".updatecom #crg06").val(); var tvpins = $(".updatecom #tvpins").val(); var jointer = $(".updatecom #jointer").val(); var cquantity = $(".updatecom #conqty").val(); var nooftv = $(".updatecom #tvno").val(); var misc = $(".updatecom #misc").val(); var tcomments = $(".updatecom #tcomments").val(); var con = $(".updatecom #con").val(); //alert(tno+status+tname+rg11+rg06+tvpins+jointer+cquantity+nooftv+misc+tcomments+con); $.ajax( { type: "POST", url: "up_functions.php", data: "ticket="+ tno +"& opt=upcom" +"& status="+ status +"& tname="+ tname +"& rg11="+ rg11 +"& rg06="+ rg06 +"& tvpins="+ tvpins +"& jointer="+ jointer +"& cquantity="+ cquantity +"& nooftv="+ nooftv +"& misc="+ misc +"& tcomments="+ tcomments +"& con="+ con, success: function(response) { alert(response); } }); } here is my up_functions.php $tno = htmlspecialchars(trim($_REQUEST['ticket'])); $status = htmlspecialchars(trim($_REQUEST['status'])); $tname = htmlspecialchars(trim($_REQUEST['tname'])); $rg11 = htmlspecialchars(trim($_REQUEST['rg11'])); $rg06 = htmlspecialchars(trim($_REQUEST['rg06'])); $tvpins = htmlspecialchars(trim($_REQUEST['tvpins'])); $jointer = htmlspecialchars(trim($_REQUEST['jointer'])); $cquantity = htmlspecialchars(trim($_REQUEST['cquantity'])); $nooftv = htmlspecialchars(trim($_REQUEST['nooftv'])); $misc = htmlspecialchars(trim($_REQUEST['misc'])); $tcomments = htmlspecialchars(trim($_REQUEST['tcomments'])); $con = htmlspecialchars(trim($_REQUEST['con'])); $result=$ptr->upcomticketinfo($tno,$status,$tname,$rg11,$rg06,$tvpins,$jointer,$cquantity,$nooftv,$misc,$tcomments,$con); echo $result; and here is my upconticketinfo() php function function upcomticketinfo($tno,$status,$tname,$rg11,$rg06,$tvpins,$jointer,$cquantity,$nooftv,$misc,$tcomments,$con) { if($con!='' || $con!=NULL) { $this->query = "update `booking discription` set `STATUS`='$status',`CLOSED ON`='$con' where `TICKET NO`='$tno'"; $this->q_result = mysql_query($this->query,$this->conn) or die(mysql_error()); if($this->q_result) { $query = "update `tech detail` set `TECH NAME`='$tname',`CABLE RG11`='$rg11',`CABLE RG06`='$rg06',`TV PINS USED`='$tvpins',`JOINTER USED`='$jointer',`CONNECTOR QTY`='$cquantity',`NO OF TV`='$nooftv',`MISC`='$misc',`TECH COMMENTS`='$tcomments' where `BOOKING`='$tno'"; $q_result = mysql_query($query,$this->conn) or die(mysql_error()); if($q_result) { $response = "updated"; } else { $response = "error"; } } else { $response = "error"; } } else { $this->query = "update `booking discription` set `STATUS`='$status' where `TICKET NO`='$tno'"; $this->q_result = mysql_query($this->query,$this->conn) or die(mysql_error()); if($this->q_result) { $query = "update `tech detail` set `TECH NAME`='$tname',`CABLE RG11`='$rg11',`CABLE RG06`='$rg06',`TV PINS USED`='$tvpins',`JOINTER USED`='$jointer',`CONNECTOR QTY`='$cquantity',`NO OF TV`='$nooftv',`MISC`='$misc',`TECH COMMENTS`='$tcomments' where `BOOKING`='$tno'"; $q_result = mysql_query($query,$this->conn) or die(mysql_error()); if($q_result) { $response = "updated"; } else { $response = "error"; } } else { $response = "error"; } } return $response; } Question is that, this code is working just fine in IE8 i.e i am using... but it is not working in FF 3.6.3... I have checked each n everything... One thing is that the code works fine on FF too only when i activate the firebug debugger. Otherwise the alert in ajax success shows itself with nothing in it... Help me...

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  • Referencing variables in a structure / C++

    - by user1628622
    Below, I provided a minimal example of code I created. I managed to get this code working, but I'm not sure if the practice being employed is sound. In essence, what I am trying to do is have the 'Parameter' class reference select elements in the 'States' class, so variables in States can be changed via Parameters. Questions I have: is the approach taken OK? If not, is there a better way to achieve what I am aiming for? Example code: struct VAR_TYPE{ public: bool is_fixed; // If is_fixed = true, then variable is a parameter double value; // Numerical value std::string name; // Description of variable (to identify it by name) }; struct NODE{ public: VAR_TYPE X, Y, Z; /* VAR_TYPE is a structure of primitive types */ }; class States{ private: std::vector <NODE_ptr> node; // shared ptr to struct NODE std::vector <PROP_DICTIONARY_ptr> property; // CAN NOT be part of Parameter std::vector <ELEMENT_ptr> element; // CAN NOT be part of Parameter public: /* ect */ void set_X_reference ( Parameter &T , int i ) { T.push_var( &node[i]->X ); } void set_Y_reference ( Parameter &T , int i ) { T.push_var( &node[i]->Y ); } void set_Z_reference ( Parameter &T , int i ) { T.push_var( &node[i]->Z ); } bool get_node_bool_X( int i ) { return node[i]->X.is_fixed; } // repeat for Y and Z }; class Parameter{ private: std::vector <VAR_TYPE*> var; public: /* ect */ }; int main(){ States S; Parameter P; /* Here I initialize and set S, and do other stuff */ // Now I assign components in States to Parameters for(int n=0 ; n<S.size_of_nodes() ; n++ ){ if ( S.get_node_bool_X(n)==true ){ S.set_X_reference ( P , n ); }; // repeat if statement for Y and Z }; /* Now P points selected to data in S, and I can * modify the contents of S through P */ return 0; }; Update The reason this issue cropped up is I am working with Fortran legacy code. To sum up this Fotran code - it's a numerical simulation of a flight vehicle. This code has a fairly rigid procedural framework one must work within, which comes with a pre-defined list of allowable Fortran types. The Fortran glue code can create an instance of a C++ object (in actuality, a reference from the perspective of Fortran), but is not aware what is contained in it (other means are used to extract C++ data into Fortran). The problem that I encountered is when a C++ module is dynamically linked to the Fortran glue code, C++ objects have to be initialized each instance the C++ code is called. This happens by virtue of how the Fortran template is defined. To avoid this cycle of re-initializing objects, I plan to use 'State' as a container class. The Fortran code allows a 'State' object, which has an arbitrary definition; but I plan to use it to harness all relevant information about the model. The idea is to use the Parameters class (which is exposed and updated by the Fortran code) to update variables in States.

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