CacheSentry for Internet Explorer |
Current Version: | 1.59, Build 162 |
Requirements: | Windows 95, 98, 98SE, ME, NT, 2K or XP, and Internet Explorer 3.0 or greater. |
Author: | David M. Pochron |
CONTENTS |
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OVERVIEW |
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This is a program that fixes serious bugs in the Internet Explorer cache manager (versions 3.0 on up through and including Internet Explorer for Windows XP, and IE6). This program basically takes over the job of managing the cache from Internet Explorer, and the result is your web browsing session will be more enjoyable. CacheSentry isn't like those "web accelleration" programs that hook into IE and attempt to make guesses about your browsing habits. CacheSentry simply does a better job of removing files from the cache, and fixes a few other bugs present in most versions of Internet Explorer.
The list of Internet Explorer bugs CacheSentry fixes: (Click on each link for the details)
In addition to fixing bugs, CacheSentry also reports some useful information to you, such as the true location of your cache folder, the current amount of space your cached files are using, and information about the volume in which the cache folder is kept. The latest versions of CacheSentry also remove Cookie files that haven't been used for months.
INSTALLATION |
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Zip: If you download the .ZIP package, you can install it by simply unzipping the contents to a folder of your choice and running the program from there. You may optionally create shortcuts to the program if you don't want to go into the CacheSentry folder to run the program every time you need it.
Installer: Note that you must have the Windows Installer 2.0 package installed on your system for this to work. (You can tell if you do not have the installer as double-clicking the CacheSentry installation file will cause Windows to ask which program to use to open the .msi file instead of doing the install. Also if you don't have version 2.0 it will give an error message telling you to download the latest version.) If you do not have the Windows Installer 2.0, you can download it from Microsoft at:
For Win 9x & ME: http://www.microsoft.com/downloads/release.asp?ReleaseID=32831
For NT4 and 2000: http://www.microsoft.com/downloads/release.asp?ReleaseID=32832
Note that Microsoft's installer package is somewhat large. If you
do not wish to go through the trouble of adding Windows Installer 2.0 to your
system, download the .ZIP package instead and install it manually.
After CacheSentry is installed, you simply run it and it will do its thing. There are a few things you must do first in order to have it function properly:
Since CacheSentry is a very small program (approx. 64K) and doesn't use anything else but the system .DLL's, leaving it running even when you're not browsing will not affect you computer's performance. In fact, CacheSentry "sleeps" until you actually start browsing with Internet Explorer on the web! (It uses no CPU cycles when it's not needed.) Once you finish using Internet Explorer, it goes back to sleep.
Once CacheSentry is installed and running, you will see a little icon appear in the tray area of the desktop taskbar. This icon lets you know CacheSentry is running and gives you access to its options window.
If you installed it using the .ZIP file, simply delete the CacheSentry folder and remove any shortcuts in the Start menu you may have created manually. If you installed using the installer, use the usual Add/Remove Programs Control Panel applet and select CacheSentry from the list of programs to remove. Note that any shortcuts you create manually will also have to be manually deleted - the uninstaller only removes the shortcut it creates for itself from the Start Menu. The uninstaller also cleans up the two registry keys CacheSentry creates leaving your system as it was before CacheSentry was installed. (If you use the .ZIP file, you'll have to find the "CacheSentry:" keys in the registry and delete them yourself if you do not want them loitering around.)
Using CacheSentry |
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With CacheSentry running, your Internet cache is automatically being managed. You can change the settings of CacheSentry by double-left-clicking or single-right-clicking with the mouse on its little icon in the taskbar.
You will then be presented with the CacheSentry properties window. By default, CacheSentry sets the cache size to whatever amount of space the cache is currently using. So if you have 10 megabytes of files currently in the cache, it considers 10 megabytes to be a full cache. If there are 100 megabytes of files in your cache, then 100 megabytes will be the set size of the cache. You can adjust this default to other sizes you like if you wish. Note that it will not allow the cache to be set larger than 700 megabytes.
All settings you use with CacheSentry will be remembered for the next time the program is run.
Informational
Displays
In the Current cache size display line, CacheSentry not only displays
the current size of the cache in bytes, but also in megabytes. Remember, a
megabyte is equal to 1,048,576 bytes (not 1,000,000 bytes), so the value here
may seem lower than the actual byte value. This displayed value should give you
a better idea of how close to the maximum size the cache is getting.
The Activity Log
The activity log reports all actions performed by the CacheSentry cache
manager, along with certain error messages. Note that it does not
display miscellaneous cache activity - this is not CacheSentry's purpose. That
functionality is the purpose
CacheMonitor. Note that you will not see any deletions logged until the
cache fills up and CacheSentry needs to make more room. This may take quite a
while if you have set the cache to a large maximum size and it is empty or near
empty. If you wish, you can clear the contents of the activity log by clicking
the "Clear Activity Log" button. CacheSentry also allows you to save the
contents of the Activity Window to a text file. This is to help with technical
support questions. It is always saved to a file named "Activity.txt", and is
saved in whatever current directory CacheSentry is set to run in. If you have
trouble locating where the file was saved, use the Windows "Find" or "Search"
command on the Desktop Start Menu.
CacheSentry places a "startup code" number in the log. If you submit tech support questions, please give us your startup code value so we may expedite a solution to your problem. (Make sure you copy the value exactly as it is shown!)
CacheSentry removes stray files and URL's. (See the Overview section for details on this.) The amount of wasted space and URL's reclaimed is displayed in the activity log. The check and removal of stray files and URL's is done when CacheSentry starts up and daily during the first scan done after midnight GMT.
As of version 1.54, you can now filter what types of stray files CacheSentry should work on. You can completely disable stray file and URL removal, only remove stray files that are zero bytes in size (this will clear most of the stray files generated by the Outlook Express bug but leave the other incomplete files actiually downloaded from web sites intact), remove only stray URL's, remove all stray files (but not stray URL's), and finally the default behavior - remove all stray files and all stray URL's. If you choose to remove only zero-byte stray files, CacheSentry will not list the other stray files it finds. However it will display the total amount of stray files (zero-byte and non-zero-byte) in the activity window after startup. If you disable stray file removal, CacheSentry lists the files it found as stray in the activity window, but takes no further action on them.
Activity Icons
CacheSentry lets you know what it's doing while it's sitting up there
in the system tray. Here is a list of icons and their meanings:
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Waiting | CacheSentry is awake but is waiting (idle) for its next crack at checking on and/or managing the cache. |
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Sleeping | CacheSentry has gone to sleep because you aren't web browsing or haven't clicked on any links for a while in the web browser. |
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Working | CacheSentry is scanning, managing, and/or removing the oldest files from the cache. This icon appears only briefly because it doesn't take long for CacheSentry to do its work - it's a very CPU-friendly program! |
If you hold the mouse pointer over the activity icon in the task bar tray, it will tell you the sum of the size of all the files in the cache. It's a very handy way of quickly seeing how large your cache has grown.
Immediate Mode
CacheSentry has an alternate mode it can run in - Immediate Mode. With
this mode, CacheSentry exits after checking to see if the Cache is larger than
the user-specified size and doing any necessary deletions. There is no user
interface nor any system tray icon display with this mode - it quietly starts
up, does its job, and leaves.
To access this mode, add the -i command line switch when starting CacheSentry, like this:
CacheSentry.exe -i
You would do this in either a shortcut (say, the Programs -> Startup folder in the Start Menu) or in a scheduling program like the Windows Task Scheduler.
The idea behind this mode is to give users the ability to control when CacheSentry does its management tasks, and not take up any memory at all when it isn't needed. For instance, let's say you have a large hard drive with space to spare and you regularly log on or restart your computer fairly often. Let's also say you have plenty of spare space available for the cache on your hard drive. You could create a shortcut to CacheSentry (or edit the existing one) in the Startup folder (as described in the INSTALLATION section) with the -i switch added. Then, whenever you restart your computer or log on as a new user, CacheSentry would be run and would do any management at just those times, bringing the cache back down to a reasonable size from the previous session of web browsing and cleaning up stray files.
Alternatively, if you do use a program like the Task Scheduler, you could put CacheSentry into its schedule to clean the cache up hourly, daily, weekly, or whatever you feel like.
Since CacheSentry has no interface in Immediate Mode, simply run CacheSentry in regular mode (i.e., without the -i switch) to set the cache size, then exit it.
If CacheSentry is already running in regular mode, it won't run in Immediate Mode - the new immediate instance of the program will just exit without doing anything. (The previous instance of CacheSentry in regular mode will be unaffected.)
Kiosk Mode
CacheSentry can be run in a "kiosk mode." The only difference between kiosk
mode and normal mode is in kiosk mode, no error dialogs appear. Instead, errors
messages are quietly inserted into the activity log. To activate kiosk mode,
specify the -k switch when invoking CacheSentry from the
Explorer Run menu item, command line prompt, or a shortcut. Example:
CacheSentry.exe -k
Other Command Line Options
As of version 1.56, the inital delay before the first
scan is done can be specified with the -d option. Immediately follow the 'd'
with the number of seconds you want CacheSentry to wait before attempting the
first scan. This delay is present to avoid thrashing of the hard drive when
CacheSentry is run from the Startup folder. You can turn this delay off
entirely if you specify zero seconds for the delay. If this option is not
specified, CacheSentry waits 5 seconds before doing the initial scan of the
cache. Example usage in a shortcut or from the command line prompt for a 12
second delay:
"C:\Program Files\CacheSentry\CacheSentry.exe" -d12
As of version 1.57, CacheSentry now accepts a -L option which will cause all text that gets displayed in the Activity Window to be output to a file named "CSLog.txt". You can use this in conjunction with the -i option if you want to see what happened when you ran CacheSentry in Immediate Mode or if you want to see all activity and not just the last 200 events.
SPECIAL NOTES |
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INTERNET EXPLORER 5.x |
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Many users have been wondering whether CacheSentry is still needed with IE5. The short answer? Yes, at least as a repair tool used on occasion. IE5 still has the stray file problem to an extent (it eventually deletes some of the strays, but for some reason others never seem to get deleted) so you'll still want to run CacheSentry from time to time just to keep the cache clean. As for it removing the wrong files when the cache fills up - they changed how it works, but it still uses a poor decision method. Here are some basic rules you can use to decide whether to continue using CacheSentry all the time or not:
In any case, IE5 does do a better job of not deleting subscribed content. I wish it made better choices about which files to delete, however. (It could be a lot better!) The stray files are still a problem, though now when you tell IE5 to delete all the files in the cache, it really does delete all the files, including the strays.
With the newly found bug regard how large IE thinks the cache is, it is necessary once again to run CacheSentry at least on a semi-regular basis to make sure you are getting full use out of the space you have allocated to the Internet cache.
IE 5.5 and 5.5 SP1
If you don't want the files Outlook Express is generating in the cache to stay around, you can run CacheSentry to clean them out for you. Because IE 5.5 seems to delete files even more randomly than IE 5 and 5.01 did, you might want to run CacheSentry while browsing if you want normal Internet content to be available in the cache for a longer period of time. IE 5.5 appears to have the same INDEX.DAT bug found in IE 4 and 5.0/5.01. Over time, the size IE thinks the cache is slowly gets out of sync with what the sum total size of all the content (including strays) actually is.
INTERNET EXPLORER 6 AND WINDOWS XP |
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Many have been asking about CacheSentry, IE6 (including the one built into XP), and whether CacheSentry works and is still needed with this new version of the browser. CacheSentry will work fine with IE6 and also with Windows XP. The problems in previous versions of IE are still present in IE6 and XP, therefore CacheSentry is still necessary. Note that with Windows XP when you see a "blue screen of death" fatal system error message, the operating system will often delete the cache in case the crash is related to a corrupt index.dat file. So if you see your cache suddenly clear itself and you recently suffered from a fatal system error, this may be why that happened.
FREQUENTLY ASKED QUESTIONS (FAQ) |
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Q: If I set Internet Explorer's cache
to 100%, won't that use up all my hard drive space?
A: No. Setting it that way only tells how much space it can
use, not how much it will use. Since you will have set CacheSentry's
size to a much smaller value, the cache will never grow that large. This
setting of IE's cache size to the largest it will go is how CacheSentry
maintains control of the cache - IE doesn't get a chance to make room in the
cache (and make random deletions in the process.) I cannot stress this point
enough - make sure you set IE's cache size as large as possible, and make sure
there is a large difference between it and CacheSentry's cache size.
Q: I'm seeing my cache suddenly drop in
size from time to time. Is something wrong?
A: Probably not. CacheSentry holds off on deleting large files
for at least 24 hours. This is done to prevent accidental erasure of these
files in case it is a failed download. (Internet Explorer 4 and up can resume
downloads in some cases.)
Q: Okay, I'm seeing the above drop as
described above and I'm also seeing CacheMonitor report deletions from all over
the cache, instead of all the oldest files grouped together. Is there a
problem?
A: Maybe. First make sure you are sorting the cache entries in
CacheMonitor by "Last Access Time". If the random deletions consist of
downloaded programs (files with .EXE or .ZIP extensions) or media files (.WAVs,
.MP3's, .MOV's, etc.) then that is normal - CacheSentry gets rid of these files
first since they are eating up most of the space in the cache and it is less
likely you will need them in the cache. Also, note that CacheSentry leaves
.class and favicon.ico files around longer than other Internet content. So if
these are the files you are not seeing get removed, that is normal. If you
still feel Internet Explorer is deleting files ahead of CacheSentry,
double-check to make sure IE's cache size setting is set to the maximum value;
or try setting CacheSentry's cache size to a smaller value.
Q: How come CacheSentry isn't reporting
any deletions? Why isn't it reporting additions to the cache?
A: The answer to the second part first: CacheSentry is not
CacheMonitor - CacheSentry does not monitor changes in the cache. It only uses
the activity window for things it does on the cache itself. As to the first
question, CacheSentry only starts removing files once the cache fills to the
limit you have set in the CacheSentry settings window. It also only checks for
stray files when it starts up and at midnight GMT. The rest of the time it will
sit quietly until it is either restarted or the cache reaches your set limit.
Q: CacheSentry says the cache is zero
bytes in size, but when I do a folder properties on the cache directory in
Windows it shows it's not empty. Why is there a discrepancy?
A: CacheSentry doesn't include the index files that are used
by IE to keep track of the cached files. (In other words, the discrepancy is
overhead used by the cache.)
Q: How do I upgrade to the latest
version of CacheSentry?
A: Simply download the latest version, then unpack/unzip the
executable programs over the old copies. Or download the installer version and
simply install over itself. (It is not necessary to uninstall first.) You can
check to make sure you are running the latest version by clicking the "About"
button in the CacheSentry settings window.