Get Mobile user access exchange server

Every administrator of exchange server happy with the GUI microsoft provided, but still command line is the best and efective way to get information from exchange.

We can scripting and automate the way we get information and dump it to a file as we like.

Come the Power Shell for exchange to the rescue. We can use Power Shell to query the exchange server to get any information we need which already provided.

Here we need to get the exchange user which using mobile device to access their inbox. The simple command are :


Get-Mailbox -ResultSize:Unlimited | ForEach {Get-ActiveSyncDeviceStatistics -Mailbox:$_.Identity} | Where {$_.LastSuccessSync -gt '2/15/2007'}
 

Then if we wan to get more granular result, we can pipe the result to another command.


Get-Mailbox -ResultSize:Unlimited | ForEach {Get-ActiveSyncDeviceStatistics -Mailbox:$_.Identity} | Where {$_.LastSuccessSync -gt '2/15/2007'} | Sort-Object -Property DeviceType,Identity | Select-Object @{name="EmailAddress";expression={$_.Identity.ToString().Split("\")[0]}},DeviceType | Export-Csv -Path:"C:\Temp\MobileDevices.csv"

With thePower Shell tools, administrator can have a time saver activity. Imagine if you need to search in 1 million of exchange user. Would you go to the Exchange GUI ? even if the GUI provide this kind of reporting.

Source of doc :
http://knicksmith.blogspot.com/2007/03/dst-and-mobile-devices.html

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Optimize squid caching Hit Rate

To optimize squid cache and get a bigger cache Hit ratio , we need to tune some configuration. The default configuration just run without optimization in cache usage and bandwith saving.

First, if our target is have a bandwidth saving, we need to configure the cache_replacement config.

The options are :

Least Recently Used (LRU)
This is the default method use by squid for cache management. Squid starts by removing the cached objects that are oldest (since the last HIT). The LRU policy utilizes the list data structure, but there is also a heap-based implementation of LRU known as heap lru.

Greedy Dual Size Frequency (GDSF)
GDSF (heap GDSF) is a heap-based removal policy. In this policy, Squid tries to keep popular objects with a smaller size in the cache. In other words, if there are two cached objects with the same popularity, the object with the larger size will be purged so that we can make space for more of the less popular objects, which will eventually lead to a better HIT ratio. While using this policy, the HIT ratio is better, but overall bandwidth savings are small.

Least frequently used with dynamic aging (LFUDA)
LFUDA (heap LFUDA) is also a heap-based replacement policy. Squid keeps the most popular objects in the cache, irrespective of their size. So, this policy compromises a bit of the HIT ratio, but may result in better bandwidth savings compared to GDSF. For example, if a cached object with a large size encounters a HIT, it'll be equal to HITs for several small sized popular objects. So, this policy tries to optimize bandwidth savings instead of the HIT ratio. We should keep the maximum object size in the cache high if we use this policy to further optimize the bandwidth savings.

So the configuration can be tuned, if you need bandwidth saving or Hit Ratio, its up to you the administrator
Here are the config for saving more bandwidth :

memory_replacement_policy     lru
cache_replacement_policy heap LFUDA

Then we need to cache the static files usually found in website as .css / .js / .jpg / .png / .gif . Usually the file rarely changed even in a dynamic websites. Some of the website provide caching information in the response the webserver provide, but sometimes they are not.

We can also override the caching information returned from a website, so we can utilize our cache server more optimal.

The config will be in refresh_pattern . With this, we can enforce the caching of some file extension, because squid use regex to match the rules we create inside squid.

The default signature are :

refresh_pattern [-i] regex min percent max [OPTIONS]

So for example we want to cache all jpg file and ignore caching options provided by the webserver response in the header, so the config will be :

refresh_pattern -i .jpg$ 0 60% 1440 ignore-no-cache ignore-no-store reload-into-ims

The meaning areit will match .jpg file with case insensitive, min time consider fresh is 0 min, and the age of file is 60% more from the Last-Modified-Date in header , and the age is more than 1440, the file considered stale in cache.

The other params is squid will ignore the header information , like ignore-no-cache , ignore-no-store .
The reload-into-ims will make squid to convert the no-cache directive in HTTP Headers to the If-Modified-Since Headers. This will used when the Last-Modified headers not available from webserver response.

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Get User in Active Directory geek way

In Windows Active Directory there are many ways to manage the data. The easiest way is use the Gui console provided by Microsoft and had been a friend to many of Windows Administrator.

But how if we need to get many of the user in single command ? Here are the command line still the most favorite choice of smart and Lazy administrator.

Here are some command to interact with Active Directory using Dsquery command. Just drop to MSDos box and query it.

To get all Group in Active Directory :

dsquery group -limit 10000 > groups.csv

To get all Users in Active Directory :

dsquery user -limit 10000 > users.csv

To get Users which  not logon in last 4 weeks :

dsquery user -inactive 4

To get all Members of a Group :

dsget group "CN=Fin,DC=asu,DC=com" -members

To get a user details in Active directory :

dsquery user -name Admin

I will post more of the usage and updated in this articles. Stay Tuned :)

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