Tag Archives: Projects - Page 2

QPerfmon 1.8.2

I made a small change to my Quick Perfmon tool so that the performance counter definition set files (qpmset files) can also save the location of the application window’s size and location. This is useful if you want it to always load up to the same position on the screen – say when you have multiple sets and you want to position a couple of these windows with a specific layout.

Go grab it here…

HTMLWriter 1.5

I’ve updated this little utility library by simplifying some method overloads plus added a static method for getting escaped html special characters.

To make the code more maintainable for the special characters (like adding new ones in the future) I’ve added an enum that use some .Net ‘attributes’ so you can see, use and reference everything about these ‘things’ in one place. To do that I had to add a special helper class so the enum can carry some additional properties (like the actual strings for the special character and the escaped string). To do this I created a custom attribute class called ‘StringValueAttribute’ like this:

public class StringValueAttribute : Attribute
{

public string StringExpandedValue;
public string StringValue;

public StringValueAttribute(string value, string stringExpandedValue)
{

this.StringValue = value;
this.StringExpandedValue = stringExpandedValue;

}

}

To retrieve the associated values from an enum another static helper class is needed: StringValueAttributeUtil

internal static class StringValueAttributeUtil
{

public static string GetStringValue(Enum value)
{

// Get the type
Type type = value.GetType();

// Get fieldinfo for this type
System.Reflection.FieldInfo fieldInfo = type.GetField(value.ToString());
// Get the stringvalue attributes
StringValueAttribute[] attribs = fieldInfo.GetCustomAttributes(
typeof(StringValueAttribute), false) as StringValueAttribute[];
// Return the first if there was a match.
return attribs.Length > 0 ? attribs[0].StringValue : null;

}
public static string GetStringExpandedValue(Enum value)
{

// Get the type
Type type = value.GetType();

// Get fieldinfo for this type
System.Reflection.FieldInfo fieldInfo = type.GetField(value.ToString());
// Get the stringvalue attributes
StringValueAttribute[] attribs = fieldInfo.GetCustomAttributes(
typeof(StringValueAttribute), false) as StringValueAttribute[];
// Return the first if there was a match.
return attribs.Length > 0 ? attribs[0].StringExpandedValue : null;

}

}

 

Then to actually make use of this helper class you decorate the enum like this: (showing only part of it…)

public enum HTMLSpecialCharacter
{

[StringValue(“<“, “&amp;lt;”)]
LessThanSign,
[StringValue(“>”, “&amp;gt;”)]
GreaterThanSign,
[StringValue(“\””, “&amp;quot;”)]
DoubleQuote,
[StringValue(“‘”, “&amp;#39;”)]
SingleQuote,

…

}

Happy HTML’ing 🙂

Update: Version 1.6 has now been released since…

Event Scavenger 4.4.1

I created a new release with only Viewer application changes. *.elvw files are now associated in Windows Explorer with the viewer so you can launch them (or from the Windows 7 jump list) and start the application with a predefined set of filters.

 

Event Scavenger 4.4

Another update to this ‘old workhorse‘ tool of mine. This time just a few UI changes to the viewer app. I changed the interface to be much more compact so the essence of the app – the list of events, is the most prominently visible by default. The detail filters can accessed by just clicking F6 or the button above the event list.

Except for the admin module where only the ‘About’ window was modified nothing else was changed.

As luck would have it, just after creating the 4.4 release I started thinking of another improvement… again with the viewer… Being able to open the .elvw from Windows Explorer with the viewer app. This way you can create short cuts to different views (say on the taskbar) or from the jump list in Windows 7.

Mail Aggregator Service on CodePlex

I’ve created a new project on CodePlex for ‘Mail Aggregator Service‘ so others can share and contribute if they want to.

There is no dedicated installer yet but installing the service is quite easy as the service exe supports my command line installation options like my other services (i.e. -install command line option).

It can be used with or without QuickMon.

I even have a new project icon/image for the project… mail gator 😉

QuickMon 2.6 released

Another quick note – QuickMon 2.6 has been released. The biggest change is the introduction of some parallel threading when calling collectors – using the .Net 4.0 parallel extensions. No new collectors or notifiers added yet.

Mail Aggregator Service update

Just a quick update. I’ve now added a ‘Sql aggregator’ as well. This means there are now 2 ways aggregated messages can be sourced – from text files or Sql server data.

The ‘sql aggregator’ can use any existing table with messages by simply adding a bit field that indicates whether or not the message (in the table) has already been sent or not. The aggregator simply calls one stored proc (or if you want to a plain tsql statement can be used but I don’t recommend it) to retrieve any messages that must be send. This list must contains a message Id, ‘to’ address, subject and a body field. How you get by them combining fields, texts and other stuff is up to the creator of the stored proc. Once sent the ‘sql aggregator’ then calls a second stored proc passing the message Id to mark the message as sent. The sql parameter must be named ‘@Id’ and be an ‘int’.

An example sql script to modify the QuickMon sql notifier table plus two stored procedures are included in the sample project.

Eample source: MailAggregator Source code

Mail Aggregator Service

One problem with creating very useful apps sometimes is that you end up making more work or trouble for yourself 🙂 My QuickMon tool has been created to help me monitor some services and ‘stuff’ which alerts me if things go pear shape… That is all good and wonderful until you (me) realize I’m beginning to ‘spam’ myself with too many messages (since I’m using smtp alerts…). Now they are all ‘valid’ alert messages and I still need to be aware of them but at some point there are just too many individual messages flying around. QuickMon alerts are quite configurable and if you want to some suppression is possible but managing this is almost a job on its own since things change with time, conditions change etc. etc. etc.

So I started thinking (an act that in itself could be dangerous at times) about how to solve the problem by grouping messages before they get sent. QuickMon itself raise alerts and immediately send them off – fire and forget style. Sure, I can build a new notifier that tries to do some batching (not sure how I can do that yet) or modify the QuickMon service itself to ‘hold on’ to alerts for time periods but that won’t be a generic solution any more. A better solution is to build a separate ‘generic’ solution that can also be used from QuickMon plus any other apps I might still create that need smtp messages to be sent out automatically (system level stuff).

This is where the idea of the MailAggregator service started. In itself it is a very simple thing – it runs, periodically checking for all messages from some ‘source’ that need to be send to the same destination, groups them as one message and sends it. The ‘source’ could be a database table or directory with files (or possibly any other place that can store a bunch of messages that can be retrieved at one time. For my own proof of concept I created a simple working example that checks for text files in a directory, use the content as the message content, group/append it, send it and then either deletes or renames the original files.

I decided to make the service a bit more dynamic in that you can add aggregators – implementing a standard interface so adding new aggregator source types in the future would be easy (like Text file and Sql table I already mentioned). Also, the service can run multiple aggregators (of the same or different types) at the same time – each serviced on its own thread (I just love threading but yeh, you have to be careful!). As with QuickMon each instance (or host as I termed it here) can have its own separate config.

So the end result of this little experiment is a working (or should I say workable) example that can already (with some electronic duck tape) be used with QuickMon alerts.

Basic architecture overview

  • MailAggregatorService

The main component of this little project is again a simple ‘Windows Service’. The service on its own is actually very simple – really just a shell that contains the aggregator hosts which calls the aggregator  libraries. A host instance gets created for every config entry (in an array) as specified in the config file.

This service also contains my code for self registration (to install it with the -install command line)

  • MailAggregatorHost

The MailAggregatorHost (class) is the container that holds the ‘aggregator source type library’. Because each source type implements a standard interface the host does not know or care which specific aggregator it is dealing with. The host is the entity that runs in a permanent loop calling the GetMessages() method of the aggregator, sends the smtp messages and then waits until the next iteration.

  • IMailAggregatorSource

Each mail aggregator source library implements the IMailAggregatorSource interface for a particular resource type a.k.a. like Text files, Sql table or whatever. The interface itself is fairly simple and has the following members:

    • event AggregatorError
    • string GetConfigIdentifierType() – will be use later to dynamically load source types
    • bool SetConfig(string config) – configure the source type with specified config
    • List<MailAggregatedMessage> GetMessages() – get the messages dub…
    • string LastError { get;set;} – not used yet but one day….
  • MailAggregatedMessage
This is just a container to hold and pass the aggregated messages from the source type to the host.
  • MailAggregatorFFSource
This is the first example implementation of the IMailAggregatorSource interface that check for plain text files (txt or anything you specify in the config) and groups them for messages. This implementation optionally checks for lines starting with ‘TO:’ and ‘SUBJECT:’. It is possible to specify default values that will be used if these lines are not available. The rest of the file is taken as the ‘body’ of the message.
By default it only groups ‘messages’ by the ‘TO’ address but you can also specify that the subject (plus TO address) will be used for the grouping. Grouped messages simple get appended.
A maximum messages size can be specified so that when a grouped set of ‘messages’ exceed the specified size a new MailAggregatedMessage instance will be created.
Once all the reading and grouping of messages have been done the processed files get either deleted or renamed as per config. When using the renaming option there is another choice – if the renamed file already exists it can either be overwritten or appended. ‘Done’ files are renamed to the original file name plus ‘.done‘.

Example source code

If you like to play with the source code yourself you need VS2010 – it requires .Net 4 (client framework)

MailAggregator

QuickMon 2.5.4

The first update to one of my tool projects on CodePlex is a QuickMon release. It is actually a very small change – bug fix of a silly little UI bug.

Hopefully I’ll have some time this year to improve the tool further – there are several ideas in the pipeline…

Event log notifier for QuickMon

I’ve eventually added an Event log notifier for QuickMon. It is actually really simple and does a basic job of logging alerts to the event log. It could be useful for those users that might not have a full SQL server database to log alerts to.

Some features:

* It use the alert level for the event log entry ‘type’ – like warning or error.
* You can log events to the local and remote event logs – but remember the permissions!
* The event source can be customized – including 2 macros for specifying the collector name or type.

Have fun monitoring!