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  • Are there any protocols/standards on top of TCP optimized for high throughput and low latency?

    - by Nosrama
    Are there any protocols/standards that work over TCP that are optimized for high throughput and low latency? The only one I can think of is FAST. At the moment I have devised just a simple text-based protocol delimited by special characters. I'd like to adopt a protocol which is designed for fast transfer and supports perhaps compression and minification of the data that travels over the TCP socket.

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  • How to launch from Eclipse in Low priority under Windows?

    - by adum
    I'm running programs from Eclipse (on Windows) that eat a lot of CPU time. To avoid bogging down my whole machine, I set the priority to Low with the Task Manager. However, this is a cumbersome manual process. Is there a way Eclipse can set this priority automatically? EDIT: I realized that each particular launcher (Java, Python etc) has its own configuration method, so I will restrict this question to the Java domain, which is what I need most.

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  • Partition Table and Exadata Hybrid Columnar Compression (EHCC)

    - by Bandari Huang
    Create EHCC table CREATE TABLE ... COMPRESS FOR [QUERY LOW|QUERY HIGH|ARCHIVE LOW|ARCHIVE HIGH]; select owner,table_name,compress_for DBA_TAB_SUBPARTITIONS where compression = ‘ENABLED'; Convert Table/Partition/Subpartition to EHCC Compress Table&Partition&Subpartition to EHCC: ALTER TABLE table_name MOVE COMPRESS FOR [QUERY LOW|QUERY HIGH|ARCHIVE LOW|ARCHIVE HIGH] [PARALLEL <dop>]; ALTER TABLE table_name MOVE PARATITION partition_name COMPRESS FOR [QUERY LOW|QUERY HIGH|ARCHIVE LOW|ARCHIVE HIGH] [PARALLEL <dop>]; ALTER TABLE table_name MOVE SUBPARATITION subpartition_name COMPRESS FOR [QUERY LOW|QUERY HIGH|ARCHIVE LOW|ARCHIVE HIGH] [PARALLEL <dop>]; select owner,table_name,compress_for DBA_TAB_SUBPARTITIONS where compression = ‘ENABLED'; select table_owner,table_name,partition_name,compress_for DBA_TAB_PARTITIONS where compression = ‘ENABLED’; select table_owner,table_name,subpartition_name,compress_for DBA_TAB_SUBPARTITIONS where compression = ‘ENABLED’; Rebuild Unusable Index: select index_name from dba_index where status = 'UNUSABLE'; select index_name,partition_name from dba_ind_partition where status = 'UNUSABLE'; select index_name,subpartition_name from dba_ind_partition where status = 'UNUSABLE'; ALTER INDEX index_name REBUILD [PARALLEL <dop>]; ALTER INDEX index_name REBUILD PARTITION partition_name [PARALLEL <dop>]; ALTER INDEX index_name REBUILD SUBPARTITION subpartition_name [PARALLEL <dop>]; Convert Table/Partition/Subpartition from EHCC to OLTP compression or uncompressed format: Uncompress EHCC Table&Partition&Subpartition: ALTER TABLE table_name MOVE [NOCOMPRESS|COMPRESS for OLTP] [PARALLEL <dop>]; ALTER TABLE table_name MOVE PARTITION partition_name [NOCOMPRESS|COMPRESS for OLTP] [PARALLEL <dop>]; ALTER TABLE table_name MOVE SUBPARTITION subpartition_name [NOCOMPRESS|COMPRESS for OLTP] [PARALLEL <dop>]; select owner,table_name,compress_for DBA_TAB_SUBPARTITIONS where compression = ''; select table_owner,table_name,partition_name,compress_for DBA_TAB_PARTITIONS where compression = ''; select table_owner,table_name,subpartition_name,compress_for DBA_TAB_SUBPARTITIONS where compression = ''; Rebuild Unusable Index: select index_name from dba_index where status = 'UNUSABLE'; select index_name,partition_name from dba_ind_partition where status = 'UNUSABLE'; select index_name,subpartition_name from dba_ind_partition where status = 'UNUSABLE'; ALTER INDEX index_name REBUILD [PARALLEL <dop>]; ALTER INDEX index_name REBUILD PARTITION partition_name [PARALLEL <dop>]; ALTER INDEX index_name REBUILD SUBPARTITION subpartition_name [PARALLEL <dop>];

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  • Two network cards latency

    - by Ross W
    I'm trying to setup a network architecture where one network is a low-latency low-bandwidth tcp control system (GBit), the other is a high-bandwidth udp (maybe tcp) network that could get saturated (GBit). If I have two NICs inside a server running Linux. What happens to the low-bandwidth/low-latency network when the high-bandwidth gets saturated. Does each Ethernet card get the same amount of priority inside the kernel or would the low-latency network suffer from the high-bandwidth being saturated?

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  • transfer database from local machine to hosting server

    - by c11ada
    hey all, im trying to transfer my database from local machine to server, im using the publish to provider wizard in visual web developer to generate a scrip, im then using the generated script on the serever database. i keep getting the following error can some one please tell where im going wrong Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_RemoveUsersFromRoles, Line 53 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_RemoveUsersFromRoles, Line 58 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_RemoveUsersFromRoles, Line 87 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_RemoveUsersFromRoles, Line 92 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_AddUsersToRoles, Line 48 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_AddUsersToRoles, Line 52 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_AddUsersToRoles, Line 79 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_AddUsersToRoles, Line 83 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 468, Level 16, State 9, Procedure aspnet_UsersInRoles_AddUsersToRoles, Line 93 Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation. Msg 15151, Level 16, State 1, Line 1 Cannot find the object 'aspnet_UsersInRoles_AddUsersToRoles', because it does not exist or you do not have permission. Msg 15151, Level 16, State 1, Line 1 Cannot find the object 'aspnet_UsersInRoles_RemoveUsersFromRoles', because it does not exist or you do not have permission. thanks

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  • Where does java.util.logging.Logger store their log

    - by Harry Pham
    This might be a stupid question but I am a bit lost with java Logger private static Logger logger = Logger.getLogger("order.web.OrderManager"); logger.info("Removed order " + id + "."); Where do I see the log? Also this quote from java.util.logging.Logger library: On each logging call the Logger initially performs a cheap check of the request level (e.g. SEVERE or FINE) against the effective log level of the logger. If the request level is lower than the log level, the logging call returns immediately. After passing this initial (cheap) test, the Logger will allocate a LogRecord to describe the logging message. It will then call a Filter (if present) to do a more detailed check on whether the record should be published. If that passes it will then publish the LogRecord to its output Handlers. Does this mean that if I have 3 request level log: logger.log(Level.FINE, "Something"); logger.log(Level.WARNING, "Something"); logger.log(Level.SEVERE, "Something"); And my log level is SEVERE, I can see all three logs, if my log level is WARNING, then I cant see SEVERE log, is that correct? And how do I set the log level?

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  • TableTools only exporting single header row

    - by Rakeesh
    I am using the DataTable jquery plugin from: http://datatables.net/ I have a DataTable that has multi-row table header with colspan. Something like: <thead> <tr> <th>Level 1</th> <th colspan='2'>Level 1 - Item 1</th> <th colspan='2'>Level 1 - Item 2</th> </tr> <tr> <th>Level 2</th> <th>Level 2 - Item 1a</th> <th>Level 2 - Item 1b</th> <th>Level 2 - Item 2a</th> <th>Level 2 - Item 2b</th> </tr> </thead> However when I use the TableTools plugin to export then except for the "Print" option all the rest (Excel, CSV, Pdf etc) only has the "Level 2" header row and not the Level 1. Any suggestions on how to get it to export also Level 1?

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  • How does Batcher Merge work at a high level?

    - by Mike
    I'm trying to grasp the concept of a Batcher Sort. However, most resources I've found online focus on proof entirely or on low-level pseudocode. Before I look at proofs, I'd like to understand how Batcher Sort works. Can someone give a high level overview of how Batcher Sort works(particularly the merge) without overly verbose pseudocode(I want to get the idea behind the Batcher Sort, not implement it)? Thanks!

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  • Msg 10054, Level 20, State 0, Line 0 Error when altering a stored procedure to add a couple of curso

    - by doug_w
    We have a home-rolled backup stored procedure that uses xp_cmdshell to create and clean up database backups. We have an instance that is 2005 sp3 that we are trying to deploy this script to. I am at a bit of a loss for why it is not working. When I execute the create it runs for about 30 seconds and yields the following error: Msg 10054, Level 20, State 0, Line 0 A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.) In my tinkering I discovered that by removing the cursors that actually do the work it will allow me to create the stored procedure (not very helpful for me though). If I add the cursors back in using an alter the error returns. I would be curious if someone has experienced this problem and knows of a solution or work around. I am not opposed to posting the source, it is just lengthy. Things I have checked: Error Logs No dump files in the log directory Thanks in advance for the help.

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  • What are good or interesting Assembler-like languages, but at a higher level?

    - by CodexArcanum
    I've been looking at L.in.oleum and am intrigued by it's mix of higher-level constructs (loops, dynamic variables) with low-level assembler power (registers). Are there other languages like Lino out there, which blend the speed of assembler with productivity enhancing features? EDIT: I realized this kind of sounds like an ad. I'm genuinely interested in other assembler-like languages, Lino is just the only one I happen to know of.

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  • Does running a SQL Server 2005 database in compatibility level 80 have a negative impact on performa

    - by Templar
    Our software must be able to run on SQL Server 2000 and 2005. To simplify development, we're running our SQL Server 2005 databases in compatibility level 80. However, database performance seems slower on SQL 2005 than on SQL 2000 in some cases (we have not confirmed this using benchmarks yet). Would upgrading the compatibility level to 90 improve performance on the SQL 2005 servers?

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  • How to create a level with curved lines with cocos2d + Box2d on the iphone?

    - by Steven
    I'd like to create a game that has levels such as this: http://img169.imageshack.us/img169/7294/picdq.png The Player moves "flies" through the level and mustn't collide with the walls. How can I create such levels? I found that piece of software: http://www.sapusmedia.com/levelsvg/ It's not that cheap, so I wonder whether there is another way to create such a level as shown in the picture above...?

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  • Sharepoint - how to set permission level to add item but not view?

    - by Stuart
    I want to allow a certain group of users to add items to a list, but not be able to view all items. This is so I can set up a workflow with certain parts of it private. I thought it'd be possible by defining a new permission level in: http://servername/_layouts/addrole.aspx ('Add a permission level' page) However, when you select the "add items" list permission, "view items" is automatically ticked also. Anyone know a solution to this?

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  • Which Cassandra API provides the highest level of abstraction?

    - by knorv
    There are a lot of Cassandra API:s available and usually the programming language preference determines the choice of API. However, if we take the programming language component out of the equation, what Cassandra API provides the highest level of abstraction? Definition of "level of abstraction" in this context: An API providing a lot of extra goodies such as index handling, etc would be considered being at a higher abstraction layer than a bare bones "close to Thrift" API.

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  • Ingredient Substitutes while Baking

    - by Rekha
    In our normal cooking, we substitute the vegetables for the gravies we prepare. When we start baking, we look for a good recipe. At least one or two ingredient will be missing. We do not know where to substitute what to bring same output. So we finally drop the plan of baking. Again after a month, we get the interest in baking. Again one or two lack of ingredient and that’s it. We keep on doing this for months. When I was going through the cooking blogs, I came across a site with the Ingredient Substitutes for Baking: (*) is to indicate that this substitution is ideal from personal experience. Flour Substitutes ( For 1 cup of Flour) All Purpose Flour 1/2 cup white cake flour plus 1/2 cup whole wheat flour 1 cup self-rising flour (omit using salt and baking powder if the recipe calls for it since self raising flour has it already) 1 cup plus 2 tablespoons cake flour 1/2 cup (75 grams) whole wheat flour 7/8 cup (130 grams) rice flour (starch) (do not replace all of the flour with the rice flour) 7/8 cup whole wheat Bread Flour 1 cup all purpose flour 1 cup all purpose flour plus 1 teaspoon wheat gluten (*) Cake Flour Place 2 tbsp cornstarch in 1 cup and fill the rest up with All Purpose flour (*) 1 cup all purpose flour minus 2 tablespoons Pastry flour Place 2 tbsp cornstarch in 1 cup and fill the rest up with All Purpose flour Equal parts of All purpose flour plus cake flour (*) Self-rising Flour 1½ teaspoons of baking powder plus ½ teaspoon of salt plus 1 cup of all-purpose flour. Cornstarch (1 tbsp) 2 tablespoons all-purpose flour 1 tablespoon arrowroot 4 teaspoons quick-cooking tapioca 1 tablespoon potato starch or rice starch or flour Tapioca (1 tbsp) 1 – 1/2 tablespoons all-purpose flour Cornmeal (stone ground) polenta OR corn flour (gives baked goods a lighter texture) if using cornmeal for breading,crush corn chips in a blender until they have the consistency of cornmeal. maize meal Corn grits Sweeteners ( for Every 1 cup ) * * (HV) denotes Healthy Version for low fat or fat free substitution in Baking Light Brown Sugar 2 tablespoons molasses plus 1 cup of white sugar Dark Brown Sugar 3 tablespoons molasses plus 1 cup of white sugar Confectioner’s/Powdered Sugar Process 1 cup sugar plus 1 tablespoon cornstarch Corn Syrup 1 cup sugar plus 1/4 cup water 1 cup Golden Syrup 1 cup honey (may be little sweeter) 1 cup molasses Golden Syrup Combine two parts light corn syrup plus one part molasses 1/2 cup honey plus 1/2 cup corn syrup 1 cup maple syrup 1 cup corn syrup Honey 1- 1/4 cups sugar plus 1/4 cup water 3/4 cup maple syrup plus 1/2 cup granulated sugar 3/4 cup corn syrup plus 1/2 cup granulated sugar 3/4 cup light molasses plus 1/2 cup granulated white sugar 1 1/4 cups granulated white or brown sugar plus 1/4 cup additional liquid in recipe plus 1/2 teaspoon cream of tartar Maple Syrup 1 cup honey,thinned with water or fruit juice like apple 3/4 cup corn syrup plus 1/4 cup butter 1 cup Brown Rice Syrup 1 cup Brown sugar (in case of cereals) 1 cup light molasses (on pancakes, cereals etc) 1 cup granulated sugar for every 3/4 cup of maple syrup and increase liquid in the recipe by 3 tbsp for every cup of sugar.If baking soda is used, decrease the amount by 1/4 teaspoon per cup of sugar substituted, since sugar is less acidic than maple syrup Molasses 1 cup honey 1 cup dark corn syrup 1 cup maple syrup 3/4 cup brown sugar warmed and dissolved in 1/4 cup of liquid ( use this if taste of molasses is important in the baked good) Cocoa Powder (Natural, Unsweetened) 3 tablespoons (20 grams) Dutch-processed cocoa plus 1/8 teaspoon cream of tartar, lemon juice or white vinegar 1 ounce (30 grams) unsweetened chocolate (reduce fat in recipe by 1 tablespoon) 3 tablespoons (20 grams) carob powder Semisweet baking chocolate (1 oz) 1 oz unsweetened baking chocolate plus 1 Tbsp sugar Unsweetened baking chocolate (1 oz ) 3 Tbsp baking cocoa plus 1 Tbsp vegetable oil or melted shortening or margarine Semisweet chocolate chips (1 cup) 6 oz semisweet baking chocolate, chopped (Alternatively) For 1 cup of Semi sweet chocolate chips you can use : 6 tablespoons unsweetened cocoa powder, 7 tablespoons sugar ,1/4 cup fat (butter or oil) Leaveners and Diary * * (HV) denotes Healthy Version for low fat or fat free substitution in Baking Compressed Yeast (1 cake) 1 envelope or 2 teaspoons active dry yeast 1 packet (1/4 ounce) Active Dry yeast 1 cake fresh compressed yeast 1 tablespoon fast-rising active yeast Baking Powder (1 tsp) 1/3 teaspoon baking soda plus 1/2 teaspoon cream of tartar 1/2 teaspoon baking soda plus 1/2 cup buttermilk or plain yogurt 1/4 teaspoon baking soda plus 1/3 cup molasses. When using the substitutions that include liquid, reduce other liquid in recipe accordingly Baking Soda(1 tsp) 3 tsp Baking Powder ( and reduce the acidic ingredients in the recipe. Ex Instead of buttermilk add milk) 1 tsp potassium bicarbonate Ideal substitution – 2 tsp Baking powder and omit salt in recipe Cream of tartar (1 tsp) 1 teaspoon white vinegar 1 tsp lemon juice Notes from What’s Cooking America – If cream of tartar is used along with baking soda in a cake or cookie recipe, omit both and use baking powder instead. If it calls for baking soda and cream of tarter, just use baking powder.Normally, when cream of tartar is used in a cookie, it is used together with baking soda. The two of them combined work like double-acting baking powder. When substituting for cream of tartar, you must also substitute for the baking soda. If your recipe calls for baking soda and cream of tarter, just use baking powder. One teaspoon baking powder is equivalent to 1/4 teaspoon baking soda plus 5/8 teaspoon cream of tartar. If there is additional baking soda that does not fit into the equation, simply add it to the batter. Buttermilk (1 cup) 1 tablespoon lemon juice or vinegar (white or cider) plus enough milk to make 1 cup (let stand 5-10 minutes) 1 cup plain or low fat yogurt 1 cup sour cream 1 cup water plus 1/4 cup buttermilk powder 1 cup milk plus 1 1/2 – 1 3/4 teaspoons cream of tartar Plain Yogurt (1 cup) 1 cup sour cream 1 cup buttermilk 1 cup crème fraiche 1 cup heavy whipping cream (35% butterfat) plus 1 tablespoon freshly squeezed lemon juice Whole Milk (1 cup) 1 cup fat free milk plus 1 tbsp unsaturated Oil like canola (HV) 1 cup low fat milk (HV) Heavy Cream (1 cup) 3/4 cup milk plus 1/3 cup melted butter.(whipping wont work) Sour Cream (1 cup) (pls refer also Substitutes for Fats in Baking below) 7/8 cup buttermilk or sour milk plus 3 tablespoons butter. 1 cup thickened yogurt plus 1 teaspoon baking soda. 3/4 cup sour milk plus 1/3 cup butter. 3/4 cup buttermilk plus 1/3 cup butter. Cooked sauces: 1 cup yogurt plus 1 tablespoon flour plus 2 teaspoons water. Cooked sauces: 1 cup evaporated milk plus 1 tablespoon vinegar or lemon juice. Let stand 5 minutes to thicken. Dips: 1 cup yogurt (drain through a cheesecloth-lined sieve for 30 minutes in the refrigerator for a thicker texture). Dips: 1 cup cottage cheese plus 1/4 cup yogurt or buttermilk, briefly whirled in a blender. Dips: 6 ounces cream cheese plus 3 tablespoons milk,briefly whirled in a blender. Lower fat: 1 cup low-fat cottage cheese plus 1 tablespoon lemon juice plus 2 tablespoons skim milk, whipped until smooth in a blender. Lower fat: 1 can chilled evaporated milk whipped with 1 teaspoon lemon juice. 1 cup plain yogurt plus 1 tablespoon cornstarch 1 cup plain nonfat yogurt Substitutes for Fats in Baking * * (HV) denoted Healthy Version for low fat or fat free substitution in Baking Butter (1 cup) 1 cup trans-free vegetable shortening 3/4 cups of vegetable oil (example. Canola oil) Fruit purees (example- applesauce, pureed prunes, baby-food fruits). Add it along with some vegetable oil and reduce any other sweeteners needed in the recipe since fruit purees are already sweet. 1 cup polyunsaturated margarine (HV) 3/4 cup polyunsaturated oil like safflower oil (HV) 1 cup mild olive oil (not extra virgin)(HV) Note: Butter creates the flakiness and the richness which an oil/purees cant provide. If you don’t want to compromise that much to taste, replace half the butter with the substitutions. Shortening(1 cup) 1 cup polyunsaturated margarine like Earth Balance or Smart Balance(HV) 1 cup + 2tbsp Butter ( better tasting than shortening but more expensive and has cholesterol and a higher level of saturated fat; makes cookies less crunchy, bread crusts more crispy) 1 cup + 2 tbsp Margarine (better tasting than shortening but more expensive; makes cookies less crunchy, bread crusts tougher) 1 Cup – 2tbsp Lard (Has cholesterol and a higher level of saturated fat) Oil equal amount of apple sauce stiffly beaten egg whites into batter equal parts mashed banana equal parts yogurt prune puree grated raw zucchini or seeds removed if cooked. Works well in quick breads/muffins/coffee cakes and does not alter taste pumpkin puree (if the recipe can handle the taste change) Low fat cottage cheese (use only half of the required fat in the recipe). Can give rubbery texture to the end result Silken Tofu – (use only half of the required fat in the recipe). Can give rubbery texture to the end result Equal parts of fruit juice Note: Fruit purees can alter the taste of the final product is used in large quantities. Cream Cheese (1 cup) 4 tbsps. margarine plus 1 cup low-fat cottage cheese – blended. Add few teaspoons of fat-free milk if needed (HV) Heavy Cream (1 cup) 1 cup evaporated skim milk (or full fat milk) 1/2 cup low fat Yogurt plus 1/2 low fat Cottage Cheese (HV) 1/2 cup Yogurt plus 1/2 Cottage Cheese Sour Cream (1 cup) 1 cup plain yogurt (HV) 3/4 cup buttermilk or plain yogurt plus 1/3 cup melted butter 1 cup crème fraiche 1 tablespoon lemon juice or vinegar plus enough whole milk to fill 1 cup (let stand 5-10 minutes) 1/2 cup low-fat cottage cheese plus 1/2 cup low-fat or nonfat yogurt (HV) 1 cup fat-free sour cream (HV) Note: How to Make Maple Syrup Substitute at home For 1 Cup Maple Syrup 1/2 cup granulated sugar 1 cup brown sugar, firmly packed 1 cup boiling water 1 teaspoon butter 1 teaspoon maple extract or vanilla extract Method In a heavy saucepan, place the granulated sugar and keep stirring until it melts and turns slightly brown. Alternatively in another pan, place brown sugar and water and bring to a boil without stirring. Now mix both the sugars and simmer in low heat until they come together as one thick syrup. Remove from heat, add butter and the extract. Use this in place of maple syrup. Store it in a fridge in an air tight container. Even though this was posted in their site long back, I found it helpful. So posting it for you. via chefinyou . cc image credit: flickr/zetrules

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  • Back to Basics: When does a .NET Assembly Dependency get loaded

    - by Rick Strahl
    When we work on typical day to day applications, it's easy to forget some of the core features of the .NET framework. For me personally it's been a long time since I've learned about some of the underlying CLR system level services even though I rely on them on a daily basis. I often think only about high level application constructs and/or high level framework functionality, but the low level stuff is often just taken for granted. Over the last week at DevConnections I had all sorts of low level discussions with other developers about the inner workings of this or that technology (especially in light of my Low Level ASP.NET Architecture talk and the Razor Hosting talk). One topic that came up a couple of times and ended up a point of confusion even amongst some seasoned developers (including some folks from Microsoft <snicker>) is when assemblies actually load into a .NET process. There are a number of different ways that assemblies are loaded in .NET. When you create a typical project assemblies usually come from: The Assembly reference list of the top level 'executable' project The Assembly references of referenced projects Dynamically loaded at runtime via AppDomain/Reflection loading In addition .NET automatically loads mscorlib (most of the System namespace) the boot process that hosts the .NET runtime in EXE apps, or some other kind of runtime hosting environment (runtime hosting in servers like IIS, SQL Server or COM Interop). In hosting environments the runtime host may also pre-load a bunch of assemblies on its own (for example the ASP.NET host requires all sorts of assemblies just to run itself, before ever routing into your user specific code). Assembly Loading The most obvious source of loaded assemblies is the top level application's assembly reference list. You can add assembly references to a top level application and those assembly references are then available to the application. In a nutshell, referenced assemblies are not immediately loaded - they are loaded on the fly as needed. So regardless of whether you have an assembly reference in a top level project, or a dependent assembly assemblies typically load on an as needed basis, unless explicitly loaded by user code. The same is true of dependent assemblies. To check this out I ran a simple test: I have a utility assembly Westwind.Utilities which is a general purpose library that can work in any type of project. Due to a couple of small requirements for encoding and a logging piece that allows logging Web content (dependency on HttpContext.Current) this utility library has a dependency on System.Web. Now System.Web is a pretty large assembly and generally you'd want to avoid adding it to a non-Web project if it can be helped. So I created a Console Application that loads my utility library: You can see that the top level Console app a reference to Westwind.Utilities and System.Data (beyond the core .NET libs). The Westwind.Utilities project on the other hand has quite a few dependencies including System.Web. I then add a main program that accesses only a simple utillity method in the Westwind.Utilities library that doesn't require any of the classes that access System.Web: static void Main(string[] args) { Console.WriteLine(StringUtils.NewStringId()); Console.ReadLine(); } StringUtils.NewStringId() calls into Westwind.Utilities, but it doesn't rely on System.Web. Any guesses what the assembly list looks like when I stop the code on the ReadLine() command? I'll wait here while you think about it… … … So, when I stop on ReadLine() and then fire up Process Explorer and check the assembly list I get: We can see here that .NET has not actually loaded any of the dependencies of the Westwind.Utilities assembly. Also not loaded is the top level System.Data reference even though it's in the dependent assembly list of the top level project. Since this particular function I called only uses core System functionality (contained in mscorlib) there's in fact nothing else loaded beyond the main application and my Westwind.Utilities assembly that contains the method accessed. None of the dependencies of Westwind.Utilities loaded. If you were to open the assembly in a disassembler like Reflector or ILSpy, you would however see all the compiled in dependencies. The referenced assemblies are in the dependency list and they are loadable, but they are not immediately loaded by the application. In other words the C# compiler and .NET linker are smart enough to figure out the dependencies based on the code that actually is referenced from your application and any dependencies cascading down into the dependencies from your top level application into the referenced assemblies. In the example above the usage requirement is pretty obvious since I'm only calling a single static method and then exiting the app, but in more complex applications these dependency relationships become very complicated - however it's all taken care of by the compiler and linker figuring out what types and members are actually referenced and including only those assemblies that are in fact referenced in your code or required by any of your dependencies. The good news here is: That if you are referencing an assembly that has a dependency on something like System.Web in a few places that are not actually accessed by any of your code or any dependent assembly code that you are calling, that assembly is never loaded into memory! Some Hosting Environments pre-load Assemblies The load behavior can vary however. In Console and desktop applications we have full control over assembly loading so we see the core CLR behavior. However other environments like ASP.NET for example will preload referenced assemblies explicitly as part of the startup process - primarily to minimize load conflicts. Specifically ASP.NET pre-loads all assemblies referenced in the assembly list and the /bin folder. So in Web applications it definitely pays to minimize your top level assemblies if they are not used. Understanding when Assemblies Load To clarify and see it actually happen what I described in the first example , let's look at a couple of other scenarios. To see assemblies loading at runtime in real time lets create a utility function to print out loaded assemblies to the console: public static void PrintAssemblies() { var assemblies = AppDomain.CurrentDomain.GetAssemblies(); foreach (var assembly in assemblies) { Console.WriteLine(assembly.GetName()); } } Now let's look at the first scenario where I have class method that references internally uses System.Web. In the first scenario lets add a method to my main program like this: static void Main(string[] args) { Console.WriteLine(StringUtils.NewStringId()); Console.ReadLine(); PrintAssemblies(); } public static void WebLogEntry() { var entry = new WebLogEntry(); entry.UpdateFromRequest(); Console.WriteLine(entry.QueryString); } UpdateFromWebRequest() internally accesses HttpContext.Current to read some information of the ASP.NET Request object so it clearly needs a reference System.Web to work. In this first example, the method that holds the calling code is never called, but exists as a static method that can potentially be called externally at some point. What do you think will happen here with the assembly loading? Will System.Web load in this example? No - it doesn't. Because the WebLogEntry() method is never called by the mainline application (or anywhere else) System.Web is not loaded. .NET dynamically loads assemblies as code that needs it is called. No code references the WebLogEntry() method and so System.Web is never loaded. Next, let's add the call to this method, which should trigger System.Web to be loaded because a dependency exists. Let's change the code to: static void Main(string[] args) { Console.WriteLine(StringUtils.NewStringId()); Console.WriteLine("--- Before:"); PrintAssemblies(); WebLogEntry(); Console.WriteLine("--- After:"); PrintAssemblies(); Console.ReadLine(); } public static void WebLogEntry() { var entry = new WebLogEntry(); entry.UpdateFromRequest(); Console.WriteLine(entry.QueryString); } Looking at the code now, when do you think System.Web will be loaded? Will the before list include it? Yup System.Web gets loaded, but only after it's actually referenced. In fact, just until before the call to UpdateFromRequest() System.Web is not loaded - it only loads when the method is actually called and requires the reference in the executing code. Moral of the Story So what have we learned - or maybe remembered again? Dependent Assembly References are not pre-loaded when an application starts (by default) Dependent Assemblies that are not referenced by executing code are never loaded Dependent Assemblies are just in time loaded when first referenced in code All of this is nothing new - .NET has always worked like this. But it's good to have a refresher now and then and go through the exercise of seeing it work in action. It's not one of those things we think about everyday, and as I found out last week, I couldn't remember exactly how it worked since it's been so long since I've learned about this. And apparently I'm not the only one as several other people I had discussions with in relation to loaded assemblies also didn't recall exactly what should happen or assumed incorrectly that just having a reference automatically loads the assembly. The moral of the story for me is: Trying at all costs to eliminate an assembly reference from a component is not quite as important as it's often made out to be. For example, the Westwind.Utilities module described above has a logging component, including a Web specific logging entry that supports pulling information from the active HTTP Context. Adding that feature requires a reference to System.Web. Should I worry about this in the scope of this library? Probably not, because if I don't use that one class of nearly a hundred, System.Web never gets pulled into the parent process. IOW, System.Web only loads when I use that specific feature and if I am, well I clearly have to be running in a Web environment anyway to use it realistically. The alternative would be considerably uglier: Pulling out the WebLogEntry class and sticking it into another assembly and breaking up the logging code. In this case - definitely not worth it. So, .NET definitely goes through some pretty nifty optimizations to ensure that it loads only what it needs and in most cases you can just rely on .NET to do the right thing. Sometimes though assembly loading can go wrong (especially when signed and versioned local assemblies are involved), but that's subject for a whole other post…© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET  CSharp   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • How to find entry level positions in a new city.

    - by sixtyfootersdude
    I am just graduating from a computer science degree (tomorrow is my last exam). I have been thinking about job hunting this semester but I wanted to focus on my studies and part time job so I am a bit late on the job hunt. I want to find a job in a city that I have very little professional network in (Ottawa, Ontario, Canada). How would you go about job hunting in a new city? I do not live there yet and I cannot easy go there so that makes finding places to apply a bit trickier. Normally I would ask people that I studied and worked with but I have few contacts in Ottawa. Where would you look to find jobs? I have been using Craigs-list My Universities job listings (but they are mostly focused on the east coast) This government job listing page: http://www.careerbeacon.com/ Anyone have any great job finding resources?

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