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  • nServiceBus - No all commands being received by handler

    - by SimonB
    In a test project based of the nServiceBus pub/sub sample, I've replace the bus.publish with bus.send in the server. The server sends 50 messages with a 1sec wait after each 5 (ie 10 burst of 5 messages). The client does not get all the messages. The soln has 3 projects - Server, Client, and common messages. The server and client are hosted via the nServiceBus generic host. Only a single bus is defined. Both client and server are configured to use StructureMap builder and BinarySerialisation. Server Endpoint: public class EndPointConfig : AsA_Publisher, IConfigureThisEndpoint, IWantCustomInitialization { public void Init() { NServiceBus.Configure.With() .StructureMapBuilder() .BinarySerializer(); } } Server Code : for (var nextId = 1; nextId <= 50; nextId++) { Console.WriteLine("Sending {0}", nextId); IDataMsg msg = new DataMsg { Id = nextId, Body = string.Format("Batch Msg #{0}", nextId) }; _bus.SendLocal(msg); Console.WriteLine(" ...sent {0}", nextId); if ((nextId % 5) == 0) Thread.Sleep(1000); } Client Endpoint: public class EndPointConfig : AsA_Client, IConfigureThisEndpoint, IWantCustomInitialization { public void Init() { NServiceBus.Configure.With() .StructureMapBuilder() .BinarySerializer(); } } Client Clode: public class DataMsgHandler : IMessageHandler<IDataMsg> { public void Handle(IDataMsg msg) { Console.WriteLine("DataMsgHandler.Handle({0}, {1}) - ({2})", msg.Id, msg.Body, Thread.CurrentThread.ManagedThreadId); } } Client and Server App.Config: <MsmqTransportConfig InputQueue="nsbt02a" ErrorQueue="error" NumberOfWorkerThreads="1" MaxRetries="5" /> <UnicastBusConfig DistributorControlAddress="" DistributorDataAddress=""> <MessageEndpointMappings> <add Messages="Test02.Messages" Endpoint="nsbt02a" /> </MessageEndpointMappings> </UnicastBusConfig> All run via VisualStudio 2008. All 50 messages are sent - but after the 1st or 2nd batch. only 1 msg per batch is sent? Any ideas? I'm assuming config or misuse but ....?

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  • Message queue proxy in Python + Twisted

    - by gasper_k
    Hi, I want to implement a lightweight Message Queue proxy. It's job is to receive messages from a web application (PHP) and send them to the Message Queue server asynchronously. The reason for this proxy is that the MQ isn't always avaliable and is sometimes lagging, or even down, but I want to make sure the messages are delivered, and the web application returns immediately. So, PHP would send the message to the MQ proxy running on the same host. That proxy would save the messages to SQLite for persistence, in case of crashes. At the same time it would send the messages from SQLite to the MQ in batches when the connection is available, and delete them from SQLite. Now, the way I understand, there are these components in this service: message listener (listens to the messages from PHP and writes them to a Incoming Queue) DB flusher (reads messages from the Incoming Queue and saves them to a database; due to SQLite single-threadedness) MQ connection handler (keeps the connection to the MQ server online by reconnecting) message sender (collects messages from SQlite db and sends them to the MQ server, then removes them from db) I was thinking of using Twisted for #1 (TCPServer), but I'm having problem with integrating it with other points, which aren't event-driven. Intuition tells me that each of these points should be running in a separate thread, because all are IO-bound and independent of each other, but I could easily put them in a single thread. Even though, I couldn't find any good and clear (to me) examples on how to implement this worker thread aside of Twisted's main loop. The example I've started with is the chatserver.py, which uses service.Application and internet.TCPServer objects. If I start my own thread prior to creating TCPServer service, it runs a few times, but the it stops and never runs again. I'm not sure, why this is happening, but it's probably because I don't use threads with Twisted correctly. Any suggestions on how to implement a separate worker thread and keep Twisted? Do you have any alternative architectures in mind?

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  • nServiceBus - Not all commands being received by handler

    - by SimonB
    In a test project based of the nServiceBus pub/sub sample, I've replace the bus.publish with bus.send in the server. The server sends 50 messages with a 1sec wait after each 5 (ie 10 burst of 5 messages). The client does not get all the messages. The soln has 3 projects - Server, Client, and common messages. The server and client are hosted via the nServiceBus generic host. Only a single bus is defined. Both client and server are configured to use StructureMap builder and BinarySerialisation. Server Endpoint: public class EndPointConfig : AsA_Publisher, IConfigureThisEndpoint, IWantCustomInitialization { public void Init() { NServiceBus.Configure.With() .StructureMapBuilder() .BinarySerializer(); } } Server Code : for (var nextId = 1; nextId <= 50; nextId++) { Console.WriteLine("Sending {0}", nextId); IDataMsg msg = new DataMsg { Id = nextId, Body = string.Format("Batch Msg #{0}", nextId) }; _bus.SendLocal(msg); Console.WriteLine(" ...sent {0}", nextId); if ((nextId % 5) == 0) Thread.Sleep(1000); } Client Endpoint: public class EndPointConfig : AsA_Client, IConfigureThisEndpoint, IWantCustomInitialization { public void Init() { NServiceBus.Configure.With() .StructureMapBuilder() .BinarySerializer(); } } Client Clode: public class DataMsgHandler : IMessageHandler<IDataMsg> { public void Handle(IDataMsg msg) { Console.WriteLine("DataMsgHandler.Handle({0}, {1}) - ({2})", msg.Id, msg.Body, Thread.CurrentThread.ManagedThreadId); } } Client and Server App.Config: <MsmqTransportConfig InputQueue="nsbt02a" ErrorQueue="error" NumberOfWorkerThreads="1" MaxRetries="5" /> <UnicastBusConfig DistributorControlAddress="" DistributorDataAddress=""> <MessageEndpointMappings> <add Messages="Test02.Messages" Endpoint="nsbt02a" /> </MessageEndpointMappings> </UnicastBusConfig> All run via VisualStudio 2008. All 50 messages are sent - but after the 1st or 2nd batch. only 1 msg per batch is sent? Any ideas? I'm assuming config or misuse but ....?

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  • VB dataset issue

    - by Gabriel
    Hi. The idea was to create a message box that stores my user name, message, and post datetime into the database as messages are sent. Soon came to realise, what if the user changed his name? So I decided to use the user id (icn) to identify the message poster instead. However, my chunk of codes keep giving me the same error. Says that there are no rows in the dataset ds2. I've tried my Query on my SQL and it works perfectly so I really really need help to spot the error in my chunk of codes here. Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Dim name As String Dim icn As String Dim message As String Dim time As String Dim tags As String = "" Dim strConn As System.Configuration.ConnectionStringSettings strConn = ConfigurationManager.ConnectionStrings("ufadb") Dim conn As SqlConnection = New SqlConnection(strConn.ToString()) Dim cmd As New SqlCommand("Select * From Message", conn) Dim daMessages As SqlDataAdapter = New SqlDataAdapter(cmd) Dim ds As New DataSet cmd.Connection.Open() daMessages.Fill(ds, "Messages") cmd.Connection.Close() If ds.Tables("Messages").Rows.Count > 0 Then Dim n As Integer = ds.Tables("Messages").Rows.Count Dim i As Integer For i = 0 To n - 1 icn = ds.Tables("Messages").Rows(i).Item("icn") Dim cmd2 As New SqlCommand("SELECT name FROM Member inner join Message ON Member.icn = Message.icn WHERE message.icn = @icn", conn) cmd2.Parameters.AddWithValue("@icn", icn) Dim daName As SqlDataAdapter = New SqlDataAdapter(cmd2) Dim ds2 As New DataSet cmd2.Connection.Open() daName.Fill(ds2, "PosterName") cmd2.Connection.Close() name = ds2.Tables("PosterName").Rows(0).Item("name") message = ds.Tables("Messages").Rows(i).Item("message") time = ds.Tables("Messages").Rows(i).Item("timePosted") tags = time + vbCrLf + name + ": " + vbCrLf + message + vbCrLf + tags Next txtBoard.Text = tags Else txtBoard.Text = "nothing to display" End If End Sub Help will be very much appreciated as I have been on this simple problem for 2 days.

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  • Symfony 1.3: Any opinion about this code? Coud be shorter or better?

    - by user248959
    Hi, I need your opinion about this code below. I have a list of messages: each message has a link that change the state of the message (read - non read). In the partial "_message" i have this: <div class="switching_link" id="switching_link_<?php echo $message ?>"> echo include_partial('link_switch_state', array('message' => $message)) </div> In the partial "_link_switch_state" i have this: if((int)$message->getState() == 1) { $string_state_message="non read"; } else { $string_state_message="read"; } echo link_to_remote('Mark as '.$string_state_message, array( 'url' => 'message/switchState?id='.$message->getId(), 'update' => 'switching_link_'.$message, "complete" => "switchClassMessage('$message');", )); And in message/actions/actions.class.php i have this: public function executeSwitchState(sfWebRequest $request) { // searching the message we want to change its state. $this->messages = Doctrine::getTable('Message')->findById($request->getParameter('id')); // changing the state of the message. if($this->messages[0]->getState() == 1) { $this->messages[0]->setState(0); } else { $this->messages[0]->setState(1); } $this->messages[0]->save(); // rendering the partial that shows the link ("Mark as read/non read"). return $this->renderPartial('mensaje/link_switch_state', array( 'message' => $this->messages[0])); } Regards Javi

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  • What do I need to do to set my computer as Default Gateway?

    - by Vaibhav
    We are trying to put together a box with dual LAN cards (let's say Outer and Inner), where the Inner LAN card is supposed to act as a default gateway on the network it is connected to. This box is running Ubuntu. The basic purpose for this box is to take messages generated on the inner network, do some work with them and forward them out the Outer LAN card to a server. The inner network is completely isolated with simply a regular switch connecting the Inner LAN Card with two other boxes. These other boxes either throw out multi-cast messages (which the Inner LAN Card is listening to), or send out unicast messages meant for the server which is not on this inner network. So, we need the Inner LAN Card to act as a default gateway, where these unicast messages will then be sent, and the code on the dual-LAN Card box can then intercept and forward these messages to the server. Question: 1. How do we setup the LAN Card to be default gateway (does it need some configuration on Ubuntu)? 2. Once we have this setup, is it a simple matter of listening to the interface to intercept the incoming messages? Any help (pointers in the right direction) is appreciated. Thanks.

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  • Move 53,800+ files into 54 separate folders with ~1000 files each?

    - by ane
    Trying to import 53,800+ individual files (messages) using Gmail's POP fetcher. Gmail understandably refuses, giving the error: "Too many messages to download. There are too many messages on the other server." The folder in question looks like similar to: /usr/home/customer/Maildir/cur/1203672790.V57I586f04M867101.mail.net:2,S /usr/home/customer/Maildir/cur/1203676329.V57I586f22M520117.mail.net:2,S /usr/home/customer/Maildir/cur/1203677194.V57I586f26M688004.mail.net:2,S /usr/home/customer/Maildir/cur/1203679158.V57I586f2bM182864.mail.net:2,S /usr/home/customer/Maildir/cur/1203680493.V57I586f33M740378.mail.net:2,S /usr/home/customer/Maildir/cur/1203685837.V57I586f0bM835200.mail.net:2,S /usr/home/customer/Maildir/cur/1203687920.V57I586f65M995884.mail.net:2,S ... Using the shell (tcsh, sh, etc. on FreeBSD), what one-line command can I type to split this directory full of files into separate folders so Gmail only sees 1000 messages at a time? Something with find or ls | xargs mv maybe. Whatever is fastest. The desired output directory would now look something like: /usr/home/customer/Maildir/cur/1203672790.V57I586f04M867101.mail.net:2,S /usr/home/customer/Maildir/cur/1203676329.V57I586f22M520117.mail.net:2,S ... /usr/home/customer/set1/ (contains messages 1-1000) /usr/home/customer/set2/ (contains messages 1001-2000) /usr/home/customer/set3/ (etc.) Ideally, cron could run another command to automatically reverse the process in 1000 message increments every hour. So Gmail only sees & downloads 1000 at a time.

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  • Java Spotlight Episode 57: Live From #Devoxx - Ben Evans and Martijn Verburg of the London JUG with Yara Senger of SouJava

    - by Roger Brinkley
    Tweet Live from Devoxx 11,  an interview with Ben Evans and Martijn Verburg from the London JUG along with  Yara Senger from the SouJava JUG on the JCP Executive Committee Elections, JSR 248, and Adopt-a-JSR program. Both the London JUG and SouJava JUG are JCP Standard Edition Executive Committee Members. Joining us this week on the Java All Star Developer Panel are Geertjan Wielenga, Principal Product Manger in Oracle Developer Tools; Stephen Chin, Java Champion and Java FX expert; and Antonio Goncalves, Paris JUG leader. Right-click or Control-click to download this MP3 file. You can also subscribe to the Java Spotlight Podcast Feed to get the latest podcast automatically. If you use iTunes you can open iTunes and subscribe with this link: Java Spotlight Podcast in iTunes. Show Notes News Netbeans 7.1 JDK 7 upgrade tools Netbeans First Patch Program OpenJFX approved as an OpenJDK project Devoxx France April 18-20, 2012 Events Nov 22-25, OTN Developer Days in the Nordics Nov 22-23, Goto Conference, Prague Dec 6-8, Java One Brazil, Sao Paulo Feature interview Ben Evans has lived in "Interesting Times" in technology - he was the lead performance testing engineer for the Google IPO, worked on the initial UK trials of 3G networks with BT, built award-winning websites for some of Hollywood's biggest hits of the 90s, rearchitected and reimagined technology helping some of the most vulnerable people in the UK and has worked on everything from some of the UKs very first ecommerce sites, through to multi-billion dollar currency trading systems. He helps to run the London Java Community, and represents the JUG on the Java SE/EE Executive Committee. His first book "The Well-Grounded Java Developer" (with Martijn Verburg) has just been published by Manning. Martijn Verburg (aka 'the Diabolical Developer') herds Cats in the Java/open source communities and is constantly humbled by the creative power to be found there. Currently he resides in London where he co-leads the London JUG (a JCP EC member), runs a couple of open source projects & drinks too much beer at his local pub. You can find him online moderating at the Javaranch or discussing (ranting?) subjects on the Prgorammers Stack Exchange site. Most recently he's become a regular speaker at conferences on Java, open source and software development and has recently wrapped up his first Manning title - "The Well-Grounded Java Developer" with his co-author Ben Evans. Yara Senger is the partner and director of teacher education and Globalcode, graduated from the University of Sao Paulo, Sao Carlos, has significant experience in Brazil and abroad in developing solutions to critical Java. She is the co-creator of Java programs Academy and Academy of Web Developer, accumulating over 1000 hours in the classroom teaching Java. She currently serves as the President of Sou Java. In this interview Ben, Martijn, and Yara talk about the JCP Executive Committee Elections, JSR 348, and the Adopt-a-JSR program. Mail Bag What's Cool Show Transcripts Transcript for this show is available here when available.

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  • Linq, double left join and double count

    - by Fabian Vilers
    Hi! I'm looking to translate this SQL statement to a well working & performant LINQ command. I've managed to have the first count working using the grouping count and key members, but don't know how to get the second count. select main.title, count(details.id) as details, count(messages.id) as messages from main left outer join details on main.id = details.mainid left outer join messages on details.id = messages.detailid group by main.title Any advice is welcome! Fabian

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  • Lots of questions about file I/O (reading/writing message strings)

    - by Nazgulled
    Hi, For this university project I'm doing (for which I've made a couple of posts in the past), which is some sort of social network, it's required the ability for the users to exchange messages. At first, I designed my data structures to hold ALL messages in a linked list, limiting the message size to 256 chars. However, I think my instructors will prefer if I save the messages on disk and read them only when I need them. Of course, they won't say what they prefer, I need to make a choice and justify the best I can why I went that route. One thing to keep in mind is that I only need to save the latest 20 messages from each user, no more. Right now I have an Hash Table that will act as inbox, this will be inside the user profile. This Hash Table will be indexed by name (the user that sent the message). The value for each element will be a data structure holding an array of size_t with 20 elements (20 messages like I said above). The idea is to keep track of the disk file offsets and bytes written. Then, when I need to read a message, I just need to use fseek() and read the necessary bytes. I think this could work nicely... I could use just one single file to hold all messages from all users in the network. I'm saying one single file because a colleague asked an instructor about saving the messages from each user independently which he replied that it might not be the best approach cause the file system has it's limits. That's why I'm thinking of going the single file route. However, this presents a problem... Since I only need to save the latest 20 messages, I need to discard the older ones when I reach this limit. I have no idea how to do this... All I know is about fread() and fwrite() to read/write bytes from/to files. How can I go to a file offset and say "hey, delete the following X bytes"? Even if I could do that, there's another problem... All offsets below that one will be completely different and I would have to process all users mailboxes to fix the problem. Which would be a pain... So, any suggestions to solve my problems? What do you suggest?

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  • send and receive SMS and developing a SMS panel

    - by Ali Foroughi
    i am working on a SMS panel based on .net framework.i just send some messages to my contacts and received their replies.i want to know witch received message is a reply of witch sent message. ex : if i send A and B messages to 1 contact and then it sends back to me X and Y messages as its reply ,now how i can find out X is a answer for witch one A or B messages.in other hand,what about Y message?!! I need some ideas or personal experiences about send and receive SMS and generating a SMS panel. thanks

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  • ASP.NET MVC ajax chat

    - by nccsbim071
    I built an ajax chat in one of my mvc website. everything is working fine. I am using polling. At certain interval i am using $.post to get the messages from the db. But there is a problem. The message retrieved using $.post keeps on repeating. here is my javascript code and controller method. var t; function GetMessages() { var LastMsgRec = $("#hdnLastMsgRec").val(); var RoomId = $("#hdnRoomId").val(); //Get all the messages associated with this roomId $.post("/Chat/GetMessages", { roomId: RoomId, lastRecMsg: LastMsgRec }, function(Data) { if (Data.Messages.length != 0) { $("#messagesCont").append(Data.Messages); if (Data.newUser.length != 0) $("#usersUl").append(Data.newUser); $("#messagesCont").attr({ scrollTop: $("#messagesCont").attr("scrollHeight") - $('#messagesCont').height() }); $("#userListCont").attr({ scrollTop: $("#userListCont").attr("scrollHeight") - $('#userListCont').height() }); } else { } $("#hdnLastMsgRec").val(Data.LastMsgRec); }, "json"); t = setTimeout("GetMessages()", 3000); } and here is my controller method to get the data: public JsonResult GetMessages(int roomId,DateTime lastRecMsg) { StringBuilder messagesSb = new StringBuilder(); StringBuilder newUserSb = new StringBuilder(); List<Message> msgs = (dc.Messages).Where(m => m.RoomID == roomId && m.TimeStamp > lastRecMsg).ToList(); if (msgs.Count == 0) { return Json(new { Messages = "", LastMsgRec = System.DateTime.Now.ToString() }); } foreach (Message item in msgs) { messagesSb.Append(string.Format(messageTemplate,item.User.Username,item.Text)); if (item.Text == "Just logged in!") newUserSb.Append(string.Format(newUserTemplate,item.User.Username)); } return Json(new {Messages = messagesSb.ToString(),LastMsgRec = System.DateTime.Now.ToString(),newUser = newUserSb.ToString().Length == 0 ?"":newUserSb.ToString()}); } Everything is working absloutely perfect. But i some messages getting repeated. The first time page loads i am retrieving the data and call GetMessages() function. I am loading the value of field hdnLastMsgRec the first time page loads and after the value for this field are set by the javascript. I think the message keeps on repeating because of asynchronous calls. I don't know, may be you guys can help me solve this. or you can suggest better way to implement this.

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  • Log4net: seperate log files for each class

    - by Mohsan
    hi.. i want to log messages from multiple classes. the problem is that currently i can log all messages into single file.i want to do this class A should log its messages into ALog.txt and class B should log its messages into BLog.txt please tell me the sample config file for these settings

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  • Replace between 2 items in observableArray - knockout

    - by Yojik
    im tring to Replace between 2 items in observableArray with knockout but something is wrong.. after the replace of the items ,i will change and send the displayOrder property (in both itmems) to the server (or should i take other approach for this) rankDownMessage: function () { console.log("ranking down msg"); var currentItemindex = viewModel.messages.indexOf(this); var nextItemIndex = currentItemindex + 1; viewModel.messages.replace( viewModel.messages()[nextItemIndex], viewModel.messages()[currentItemindex] ); } only the first item changed to the second item but the second item doesnt become the first one

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  • Localized text in Java

    - by Eager Learner
    My requirement is to display localized text messages in a J2EE web application. I know J2EE provides very good support for this. My question is what is the practice followed to have the localized messages stored to be used by the application. If I want to display Japanese / Chinese kind of messages which are not like English like char sets how do we get that messages/text into the properties files or Database tables.

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  • Forwarding rsyslog to syslog-ng, with FQDN and facility separation

    - by Joshua Miller
    I'm attempting to configure my rsyslog clients to forward messages to my syslog-ng log repository systems. Forwarding messages works "out of the box", but my clients are logging short names, not FQDNs. As a result the messages on the syslog repo use short names as well, which is a problem because one can't determine which system the message originated from easily. My clients get their names through DHCP / DNS. I've tried a number of solutions trying to get this working, but without success. I'm using rsyslog 4.6.2 and syslog-ng 3.2.5. I've tried setting $PreserveFQDN on as the first directive in /etc/rsyslog.conf (and restarting rsyslog of course). It seems to have no effect. hostname --fqdn on the client returns the proper FQDN, so the problem isn't whether the system can actually figure out its own FQDN. $LocalHostName <fqdn> looked promising, but this directive isn't available in my version of rsyslog (Available since 4.7.4+, 5.7.3+, 6.1.3+). Upgrading isn't an option at the moment. Configuring the syslog-ng server to populate names based on reverse lookups via DNS isn't an option. There are complexities with reverse DNS and the public cloud. Specifying for the forwarder to use a custom template seems like a viable option at first glance. I can specify the following, which causes local logging to begin using the FQDN on the syslog-ng repo. $template MyTemplate, "%timestamp% <FQDN> %syslogtag%%msg%" $ActionForwardDefaultTemplate MyTemplate However, when I put this in place syslog-ng seems to be unable to categorize messages by facility or priority. Messages come in as FQDN, but everything is put in to user.log. When I don't use the custom template, messages are properly categorized under facility and priority, but with the short name. So, in summary, if I manually trick rsyslog into including the FQDN, priority and facility becomes lost details to syslog-ng. How can I get rsyslog to do FQDN logging which works properly going to a syslog-ng repository? rsyslog client config: $ModLoad imuxsock.so # provides support for local system logging (e.g. via logger command) $ModLoad imklog.so # provides kernel logging support (previously done by rklogd) $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat *.info;mail.none;authpriv.none;cron.none /var/log/messages authpriv.* /var/log/secure mail.* -/var/log/maillog cron.* /var/log/cron *.emerg * uucp,news.crit /var/log/spooler local7.* /var/log/boot.log $WorkDirectory /var/spool/rsyslog # where to place spool files $ActionQueueFileName fwdRule1 # unique name prefix for spool files $ActionQueueMaxDiskSpace 1g # 1gb space limit (use as much as possible) $ActionQueueSaveOnShutdown on # save messages to disk on shutdown $ActionQueueType LinkedList # run asynchronously $ActionResumeRetryCount -1 # infinite retries if host is down *.* @syslog-ng1.example.com *.* @syslog-ng2.example.com syslog-ng configuration (abridged for brevity): options { flush_lines (0); time_reopen (10); log_fifo_size (1000); long_hostnames (off); use_dns (no); use_fqdn (yes); create_dirs (no); keep_hostname (yes); }; source src { unix-stream("/dev/log"); internal(); udp(ip(0.0.0.0) port(514)); }; destination per_host_destination { file( "/var/log/syslog-ng/devices/$HOST/$FACILITY.log" owner("root") group("root") perm(0644) dir_owner(root) dir_group(root) dir_perm(0775) create_dirs(yes)); }; log { source(src); destination(per_facility_destination); };

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  • Log transport and aggregation at scale

    - by markdrayton
    How're you analysing log files from UNIX/Linux machines? We run several hundred servers which all generate their own log files, either directly or through syslog. I'm looking for a decent solution to aggregate these and pick out important events. This problem breaks down into 3 components: 1) Message transport The classic way is to use syslog to log messages to a remote host. This works fine for applications that log into syslog but less useful for apps that write to a local file. Solutions for this might include having the application log into a FIFO connected to a program to send the message using syslog, or by writing something that will grep the local files and send the output to the central syslog host. However, if we go to the trouble of writing tools to get messages into syslog would we be better replacing the whole lot with something like Facebook's Scribe which offers more flexibility and reliability than syslog? 2) Message aggregation Log entries seem to fall into one of two types: per-host and per-service. Per-host messages are those which occur on one machine; think disk failures or suspicious logins. Per-service messages occur on most or all of the hosts running a service. For instance, we want to know when Apache finds an SSI error but we don't want the same error from 100 machines. In all cases we only want to see one of each type of message: we don't want 10 messages saying the same disk has failed, and we don't want a message each time a broken SSI is hit. One approach to solving this is to aggregate multiple messages of the same type into one on each host, send the messages to a central server and then aggregate messages of the same kind into one overall event. SER can do this but it's awkward to use. Even after a couple of days of fiddling I had only rudimentary aggregations working and had to constantly look up the logic SER uses to correlate events. It's powerful but tricky stuff: I need something which my colleagues can pick up and use in the shortest possible time. SER rules don't meet that requirement. 3) Generating alerts How do we tell our admins when something interesting happens? Mail the group inbox? Inject into Nagios? So, how're you solving this problem? I don't expect an answer on a plate; I can work out the details myself but some high-level discussion on what is surely a common problem would be great. At the moment we're using a mishmash of cron jobs, syslog and who knows what else to find events. This isn't extensible, maintainable or flexible and as such we miss a lot of stuff we shouldn't. Updated: we're already using Nagios for monitoring which is great for detected down hosts/testing services/etc but less useful for scraping log files. I know there are log plugins for Nagios but I'm interested in something more scalable and hierarchical than per-host alerts.

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  • WCF Publish/Subscribe and using callbacks to send data to specific users

    - by manemawanna
    Hello thanks for looking, I'm working on a project at the moment and have become a little stuck. I'm creating a client server app, which allows a client to subscribe to the server to have messages forwarded to it. The issue I'm having is that when the client subscribes I wish for them to only recieve updates that relate to them. The system basically passes messages from a SQL server DB which the server monitors. When a new message is recieved the server should only forward the message to the clients that it applys to, based on whos logged on the client machine. I've had a look and found code samples which sign up for messages to be broadcast across all clients who have subscribed, but not any that show how to identify individual clients and if messages apply to them. If anyone could help or point me in the right direction it would be appreciated. You can now find some of my code below: namespace AnnouncementServiceLibrary { [ServiceContract(CallbackContract = typeof(IMessageCallback))] public interface IMessageCheck { [OperationContract] void MessageCheck(); } } namespace AnnouncementServiceLibrary { public interface IMessageCallback { [OperationContract(IsOneWay = true)] void OnNewMessage(Mess message); } } public bool Subscribe() { try { IMessageCallback callback = OperationContext.Current.GetCallbackChannel<IMessageCallback>(); //If they dont already exist in the subscribers list, adds them to it if (!subscribers.Contains(callback)) subscribers.Add(callback); return true; } catch { //Otherwise if an error occurs returns false return false; } } Subscribe/Unsubscribe: private static readonly List<IMessageCallback> subscribers = new List<IMessageCallback>(); /// <summary> /// Unsubscribes the user from recieving new messages when they become avaliable /// </summary> /// <returns>Returns a bool that indicates whether the operation worked or not</returns> public bool Unsubscribe() { try { IMessageCallback callback = OperationContext.Current.GetCallbackChannel<IMessageCallback>(); //If they exist in the list of subscribers they are then removed if (subscribers.Contains(callback)) subscribers.Remove(callback); return true; } catch { //Otherwise if an error occurs returns false return false; } } Finally this at the moment isnt't working as basically when a user subscribes as it loops through I want it to filter based on the users userID: #region IMessageCheck Members /// <summary> /// This method checks for new messages recieved based on those who have subscribed for the service /// </summary> public void MessageCheck() { //A continuous loop to keep the method going while(true) { //Changes the thread to a sleep state for 2 mins? Thread.Sleep(200000); //Go through each subscriber based on there callback information subscribers.ForEach(delegate(IMessageCallback callback) { //Checks if the person who wanted the callback can still be communicated with if (((ICommunicationObject)callback).State == CommunicationState.Opened) { //Creates a link to the database and gets the required information List<Mess> mess = new List<Mess>(); List<Message> me; List<MessageLink> messLink; AnnouncementDBDataContext aDb = new AnnouncementDBDataContext(); me = aDb.Messages.ToList(); messLink = aDb.MessageLinks.ToList(); //Query to retrieve any messages which are newer than the time when the last cycle finished var result = (from a in messLink join b in me on a.UniqueID equals b.UniqueID where b.TimeRecieved > _time select new { b.UniqueID, b.Author, b.Title, b.Body, b.Priority, a.Read, b.TimeRecieved }); //Foreach result a new message is created and returned to the PC that subscribed foreach (var a in result) { Mess message = new Mess(a.UniqueID, a.Author, a.Title, a.Body, a.Priority, (bool)a.Read, a.TimeRecieved); callback.OnNewMessage(message); } } //If the requesting PC can't be contacted they are removed from the subscribers list else { subscribers.Remove(callback); } }); //Sets the datetime so the next cycle can measure against to see if new messages have been recieved _time = DateTime.Now; } } #endregion

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  • Java Logger API

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

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  • Service Broker, not ETL

    - by jamiet
    I have been very quiet on this blog of late and one reason for that is I have been very busy on a client project that I would like to talk about a little here. The client that I have been working for has a website that runs on a distributed architecture utilising a messaging infrastructure for communication between different endpoints. My brief was to build a system that could consume these messages and produce analytical information in near-real-time. More specifically I basically had to deliver a data warehouse however it was the real-time aspect of the project that really intrigued me. This real-time requirement meant that using an Extract transformation, Load (ETL) tool was out of the question and so I had no choice but to write T-SQL code (i.e. stored-procedures) to process the incoming messages and load the data into the data warehouse. This concerned me though – I had no way to control the rate at which data would arrive into the system yet we were going to have end-users querying the system at the same time that those messages were arriving; the potential for contention in such a scenario was pretty high and and was something I wanted to minimise as much as possible. Moreover I did not want the processing of data inside the data warehouse to have any impact on the customer-facing website. As you have probably guessed from the title of this blog post this is where Service Broker stepped in! For those that have not heard of it Service Broker is a queuing technology that has been built into SQL Server since SQL Server 2005. It provides a number of features however the one that was of interest to me was the fact that it facilitates asynchronous data processing which, in layman’s terms, means the ability to process some data without requiring the system that supplied the data having to wait for the response. That was a crucial feature because on this project the customer-facing website (in effect an OLTP system) would be calling one of our stored procedures with each message – we did not want to cause the OLTP system to wait on us every time we processed one of those messages. This asynchronous nature also helps to alleviate the contention problem because the asynchronous processing activity is handled just like any other task in the database engine and hence can wait on another task (such as an end-user query). Service Broker it was then! The stored procedure called by the OLTP system would simply put the message onto a queue and we would use a feature called activation to pick each message off the queue in turn and process it into the warehouse. At the time of writing the system is not yet up to full capacity but so far everything seems to be working OK (touch wood) and crucially our users are seeing data in near-real-time. By near-real-time I am talking about latencies of a few minutes at most and to someone like me who is used to building systems that have overnight latencies that is a huge step forward! So then, am I advocating that you all go out and dump your ETL tools? Of course not, no! What this project has taught me though is that in certain scenarios there may be better ways to implement a data warehouse system then the traditional “load data in overnight” approach that we are all used to. Moreover I have really enjoyed getting to grips with a new technology and even if you don’t want to use Service Broker you might want to consider asynchronous messaging architectures for your BI/data warehousing solutions in the future. This has been a very high level overview of my use of Service Broker and I have deliberately left out much of the minutiae of what has been a very challenging implementation. Nonetheless I hope I have caused you to reflect upon your own approaches to BI and question whether other approaches may be more tenable. All comments and questions gratefully received! Lastly, if you have never used Service Broker before and want to kick the tyres I have provided below a very simple “Service Broker Hello World” script that will create all of the objects required to facilitate Service Broker communications and then send the message “Hello World” from one place to anther! This doesn’t represent a “proper” implementation per se because it doesn’t close down down conversation objects (which you should always do in a real-world scenario) but its enough to demonstrate the capabilities! @Jamiet ----------------------------------------------------------------------------------------------- /*This is a basic Service Broker Hello World app. Have fun! -Jamie */ USE MASTER GO CREATE DATABASE SBTest GO --Turn Service Broker on! ALTER DATABASE SBTest SET ENABLE_BROKER GO USE SBTest GO -- 1) we need to create a message type. Note that our message type is -- very simple and allowed any type of content CREATE MESSAGE TYPE HelloMessage VALIDATION = NONE GO -- 2) Once the message type has been created, we need to create a contract -- that specifies who can send what types of messages CREATE CONTRACT HelloContract (HelloMessage SENT BY INITIATOR) GO --We can query the metadata of the objects we just created SELECT * FROM   sys.service_message_types WHERE name = 'HelloMessage'; SELECT * FROM   sys.service_contracts WHERE name = 'HelloContract'; SELECT * FROM   sys.service_contract_message_usages WHERE  service_contract_id IN (SELECT service_contract_id FROM sys.service_contracts WHERE name = 'HelloContract') AND        message_type_id IN (SELECT message_type_id FROM sys.service_message_types WHERE name = 'HelloMessage'); -- 3) The communication is between two endpoints. Thus, we need two queues to -- hold messages CREATE QUEUE SenderQueue CREATE QUEUE ReceiverQueue GO --more querying metatda SELECT * FROM sys.service_queues WHERE name IN ('SenderQueue','ReceiverQueue'); --we can also select from the queues as if they were tables SELECT * FROM SenderQueue   SELECT * FROM ReceiverQueue   -- 4) Create the required services and bind them to be above created queues CREATE SERVICE Sender   ON QUEUE SenderQueue CREATE SERVICE Receiver   ON QUEUE ReceiverQueue (HelloContract) GO --more querying metadata SELECT * FROM sys.services WHERE name IN ('Receiver','Sender'); -- 5) At this point, we can begin the conversation between the two services by -- sending messages DECLARE @conversationHandle UNIQUEIDENTIFIER DECLARE @message NVARCHAR(100) BEGIN   BEGIN TRANSACTION;   BEGIN DIALOG @conversationHandle         FROM SERVICE Sender         TO SERVICE 'Receiver'         ON CONTRACT HelloContract WITH ENCRYPTION=OFF   -- Send a message on the conversation   SET @message = N'Hello, World';   SEND  ON CONVERSATION @conversationHandle         MESSAGE TYPE HelloMessage (@message)   COMMIT TRANSACTION END GO --check contents of queues SELECT * FROM SenderQueue   SELECT * FROM ReceiverQueue   GO -- Receive a message from the queue RECEIVE CONVERT(NVARCHAR(MAX), message_body) AS MESSAGE FROM ReceiverQueue GO --If no messages were received and/or you can't see anything on the queues you may wish to check the following for clues: SELECT * FROM sys.transmission_queue -- Cleanup DROP SERVICE Sender DROP SERVICE Receiver DROP QUEUE SenderQueue DROP QUEUE ReceiverQueue DROP CONTRACT HelloContract DROP MESSAGE TYPE HelloMessage GO USE MASTER GO DROP DATABASE SBTest GO

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  • Computer Networks UNISA - Chap 10 &ndash; In Depth TCP/IP Networking

    - by MarkPearl
    After reading this section you should be able to Understand methods of network design unique to TCP/IP networks, including subnetting, CIDR, and address translation Explain the differences between public and private TCP/IP networks Describe protocols used between mail clients and mail servers, including SMTP, POP3, and IMAP4 Employ multiple TCP/IP utilities for network discovery and troubleshooting Designing TCP/IP-Based Networks The following sections explain how network and host information in an IPv4 address can be manipulated to subdivide networks into smaller segments. Subnetting Subnetting separates a network into multiple logically defined segments, or subnets. Networks are commonly subnetted according to geographic locations, departmental boundaries, or technology types. A network administrator might separate traffic to accomplish the following… Enhance security Improve performance Simplify troubleshooting The challenges of Classful Addressing in IPv4 (No subnetting) The simplest type of IPv4 is known as classful addressing (which was the Class A, Class B & Class C network addresses). Classful addressing has the following limitations. Restriction in the number of usable IPv4 addresses (class C would be limited to 254 addresses) Difficult to separate traffic from various parts of a network Because of the above reasons, subnetting was introduced. IPv4 Subnet Masks Subnetting depends on the use of subnet masks to identify how a network is subdivided. A subnet mask indicates where network information is located in an IPv4 address. The 1 in a subnet mask indicates that corresponding bits in the IPv4 address contain network information (likewise 0 indicates the opposite) Each network class is associated with a default subnet mask… Class A = 255.0.0.0 Class B = 255.255.0.0 Class C = 255.255.255.0 An example of calculating  the network ID for a particular device with a subnet mask is shown below.. IP Address = 199.34.89.127 Subnet Mask = 255.255.255.0 Resultant Network ID = 199.34.89.0 IPv4 Subnetting Techniques Subnetting breaks the rules of classful IPv4 addressing. Read page 490 for a detailed explanation Calculating IPv4 Subnets Read page 491 – 494 for an explanation Important… Subnetting only applies to the devices internal to your network. Everything external looks at the class of the IP address instead of the subnet network ID. This way, traffic directed to your network externally still knows where to go, and once it has entered your internal network it can then be prioritized and segmented. CIDR (classless Interdomain Routing) CIDR is also known as classless routing or supernetting. In CIDR conventional network class distinctions do not exist, a subnet boundary can move to the left, therefore generating more usable IP addresses on your network. A subnet created by moving the subnet boundary to the left is known as a supernet. With CIDR also came new shorthand for denoting the position of subnet boundaries known as CIDR notation or slash notation. CIDR notation takes the form of the network ID followed by a forward slash (/) followed by the number of bits that are used for the extended network prefix. To take advantage of classless routing, your networks routers must be able to interpret IP addresses that don;t adhere to conventional network class parameters. Routers that rely on older routing protocols (i.e. RIP) are not capable of interpreting classless IP addresses. Internet Gateways Gateways are a combination of software and hardware that enable two different network segments to exchange data. A gateway facilitates communication between different networks or subnets. Because on device cannot send data directly to a device on another subnet, a gateway must intercede and hand off the information. Every device on a TCP/IP based network has a default gateway (a gateway that first interprets its outbound requests to other subnets, and then interprets its inbound requests from other subnets). The internet contains a vast number of routers and gateways. If each gateway had to track addressing information for every other gateway on the Internet, it would be overtaxed. Instead, each handles only a relatively small amount of addressing information, which it uses to forward data to another gateway that knows more about the data’s destination. The gateways that make up the internet backbone are called core gateways. Address Translation An organizations default gateway can also be used to “hide” the organizations internal IP addresses and keep them from being recognized on a public network. A public network is one that any user may access with little or no restrictions. On private networks, hiding IP addresses allows network managers more flexibility in assigning addresses. Clients behind a gateway may use any IP addressing scheme, regardless of whether it is recognized as legitimate by the Internet authorities but as soon as those devices need to go on the internet, they must have legitimate IP addresses to exchange data. When a clients transmission reaches the default gateway, the gateway opens the IP datagram and replaces the client’s private IP address with an Internet recognized IP address. This process is known as NAT (Network Address Translation). TCP/IP Mail Services All Internet mail services rely on the same principles of mail delivery, storage, and pickup, though they may use different types of software to accomplish these functions. Email servers and clients communicate through special TCP/IP application layer protocols. These protocols, all of which operate on a variety of operating systems are discussed below… SMTP (Simple Mail transfer Protocol) The protocol responsible for moving messages from one mail server to another over TCP/IP based networks. SMTP belongs to the application layer of the ODI model and relies on TCP as its transport protocol. Operates from port 25 on the SMTP server Simple sub-protocol, incapable of doing anything more than transporting mail or holding it in a queue MIME (Multipurpose Internet Mail Extensions) The standard message format specified by SMTP allows for lines that contain no more than 1000 ascii characters meaning if you relied solely on SMTP you would have very short messages and nothing like pictures included in an email. MIME us a standard for encoding and interpreting binary files, images, video, and non-ascii character sets within an email message. MIME identifies each element of a mail message according to content type. MIME does not replace SMTP but works in conjunction with it. Most modern email clients and servers support MIME POP (Post Office Protocol) POP is an application layer protocol used to retrieve messages from a mail server POP3 relies on TCP and operates over port 110 With POP3 mail is delivered and stored on a mail server until it is downloaded by a user Disadvantage of POP3 is that it typically does not allow users to save their messages on the server because of this IMAP is sometimes used IMAP (Internet Message Access Protocol) IMAP is a retrieval protocol that was developed as a more sophisticated alternative to POP3 The single biggest advantage IMAP4 has over POP3 is that users can store messages on the mail server, rather than having to continually download them Users can retrieve all or only a portion of any mail message Users can review their messages and delete them while the messages remain on the server Users can create sophisticated methods of organizing messages on the server Users can share a mailbox in a central location Disadvantages of IMAP are typically related to the fact that it requires more storage space on the server. Additional TCP/IP Utilities Nearly all TCP/IP utilities can be accessed from the command prompt on any type of server or client running TCP/IP. The syntaxt may differ depending on the OS of the client. Below is a list of additional TCP/IP utilities – research their use on your own! Ipconfig (Windows) & Ifconfig (Linux) Netstat Nbtstat Hostname, Host & Nslookup Dig (Linux) Whois (Linux) Traceroute (Tracert) Mtr (my traceroute) Route

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  • Java SWIFT Library

    - by jkl
    I'm looking for a Java library for SWIFT messages. I want to parse SWIFT messages into an object model validate SWIFT messages (including SWIFT network validation rules) build / change SWIFT messages by using an object model Theoretically, I need to support all SWIFT message types. But at the moment I need MT103+, MT199, MT502, MT509, MT515 and MT535. So far I've looked at two libraries AnaSys Message Objects (link text) Datamation SWIFT Message Suite (link text) Both libraries allow to accomplish the tasks mentioned above but in both cases I'm not really happy. AnaSys uses a internal XML representation for all SWIFT messages which you need to know in order to access the fields of a message. And you need to operate on the DOM of the XML representation, there is no way to say "get the contents of field '50K' of the SWIFT message". And the Datamation library seems to have the nicer API but does not find all errors. So does anyone know other SWIFT libraries to use?

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  • BizTalk host throttling &ndash; Singleton pattern and High database size

    - by S.E.R.
    Originally posted on: http://geekswithblogs.net/SERivas/archive/2013/06/30/biztalk-host-throttling-ndash-singleton-pattern-and-high-database-size.aspxI have worked for some days around the singleton pattern (for those unfamiliar with it, read this post by Victor Fehlberg) and have come across a few very interesting posts, among which one dealt with performance issues (here, also by Victor Fehlberg). Simply put: if you have an orchestration which implements the singleton pattern, then performances will continuously decrease as the orchestration receives and consumes messages, and that behavior is more obvious when the orchestration never ends (ie : it keeps looping and never terminates or completes). As I experienced the same kind of problem (actually I was alerted by SCOM, which told me that the host was being throttled because of High database size), I thought it would be a good idea to dig a little bit a see what happens deep inside BizTalk and thus understand the reasons for this behavior. NOTE: in this article, I will focus on this High database size throttling condition. I will try and work on the other conditions in some not too distant future… Test conditions The singleton orchestration For the purpose of this study, I have created the following orchestration, which is a very basic implementation of a singleton that piles up incoming messages, then does something else when a certain timeout has been reached without receiving another message: Throttling settings I have two distinct hosts : one that hosts the receive port (basic FILE port) : Ports_ReceiveHostone that hosts the orchestration : ProcessingHost In order to emphasize the throttling mechanism, I have modified the throttling settings for each of these hosts are as follows (all other parameters are set to the default value): [Throttling thresholds] Message count in database: 500 (default value : 50000) Evolution of performance counters when submitting messages Since we are investigating the High database size throttling condition, here are the performance counter that we should take a look at (all of them are in the BizTalk:Message Agent performance object): Database sizeHigh database sizeMessage delivery throttling stateMessage publishing throttling stateMessage delivery delay (ms)Message publishing delay (ms)Message delivery throttling state durationMessage publishing throttling state duration (If you are not used to Perfmon, I strongly recommend that you start using it right now: it is a wonderful tool that allows you to open the hood and see what is going on inside BizTalk – and other systems) Database size It is quite obvious that we will start by watching the database size and high database size counters, just to see when the first reaches the configured threshold (500) and when the second rings the alarm. NOTE : During this test I submitted 600 messages, one message at a time every 10ms to see the evolution of the counters we have previously selected. It might not show very well on this screenshot, but here is what happened: From 15:46:50 to 15:47:50, the database size for the Ports_ReceiveHost host (blue line) kept growing until it reached a maximum of 504.At 15:47:50, the high database size alert fires At first I was surprised by this result: why is it the database size of the receiving host that keeps growing since it is the processing host that piles up messages? Actually, it makes total sense. This counter measures the size of the database queue that is being filled by the host, not consumed. Therefore, the high database size alert is raised on the host that fills the queue: Ports_ReceiveHost. More information is available on the Public MPWiki page. Now, looking at the Message publishing throttling state for the receiving host (green line), we can see that a throttling condition has been reached at 15:47:50: We can also see that the Message publishing delay(ms) (blue line) has begun growing slowly from this point. All of this explains why performances keep decreasing when a singleton keeps processing new messages: the database size grows and when it has exceeded the Message count in database threshold, the host is throttled and the publishing delay keeps increasing. Digging further So, what happens to the database queue then? Is it flushed some day or does it keep growing and growing indefinitely? The real question being: will the host be throttled forever because of this singleton? To answer this question, I set the Message count in database threshold to 20 (this value is very low in order not to wait for too long, otherwise I certainly would have fallen asleep in front of my screen) and I submitted 30 messages. The test was started at 18:26. At 18:56 (ie : exactly 30min later) the throttling was stopped and the database size was divided by 2. 30 min later again, the database size had dropped to almost zero: I guess I’ll have to find some documentation and do some more testing before I sort this out! My guess is that some maintenance job is at work here, though I cannot tell which one Digging even further If we take a look at the Message delivery throttling state counter for the processing host, we can see that this host was also throttled during the submission of the 600 documents: The value for the counter was 1, meaning that Message delivery incoming rate for the host instance exceeds the Message delivery outgoing rate * the specified Rate overdrive factor (percent) value. We will see this another day… :) A last word Let’s end this article with a warning: DO NOT CHANGE THE THROTTLING SETTINGS LIGHTLY! The temptation can be great to just bypass throttling by setting very high values for each parameter (or zero in some cases, which simply disables throttling). Nevertheless, always keep in mind that this mechanism is here for a very good reason: prevent your BizTalk infrastructure from exploding!! So whatever you do with those settings, do a lot of testing and benchmarking!

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  • Inbox Functionality with MYSQL

    - by Faisal Abid
    So I am writing a simple inbox private message system, my table schema is as follows - messageID - message - sender id - receiver id - date sent - read ( 0 = no , 1 = yes) now I am able to show the messages for the user by relating his userID to receiverID. However I also want to show the messages he has sent in the inbox to the user. For example his inbox should show Darth Vader - 3 New messages Luke - 0 new messages (0 because either I read all of them OR i sent him the message and he has not replied). But what i can only come up with is Darth Vader - 3 New messages. Can I get any help with how I can accomplish this SQL call?

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  • Objective C message dispatch mechanism

    - by Dolphin
    I am just staring to play around with Objective C (writing toy iPhone apps) and I am curious about the underlying mechanism used to dispatch messages. I have a good understanding of how virtual functions in C++ are generally implemented and what the costs are relative to a static or non-virtual method call, but I don't have any background with Obj-C to know how messages are sent. Browsing around I found this loose benchmark and it mentions IMP cached messages being faster than virtual function calls, which are in turn faster than a standard message send. I am not trying to optimize anything, just get deeper understanding of how exactly the messages get dispatched. How are Obj-C messages dispatched? How do Instance Method Pointers get cached and can you (in general) tell by reading the code if a message will get cached? Are class methods essentially the same as a C function (or static class method in C++), or is there something more to them? I know some of these questions may be 'implementation dependent' but there is only one implementation that really counts.

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