Abstract:
An information system includes a client component resident on a computer of the user, a server, and a database storage unit. The server is coupled to the computer and an internetwork such as the Internet. The server collects electronic information corresponding to a user&#39;s predetermined customized profile for delivery to the client component from the internet sites and the server. The database storage unit is coupled to the server. Electronic information collected by the server is used to populate at least one archive stored in the database storage unit. The archive is associated with the user&#39;s profile. The server sends checksums identifying the collected electronic information to the client component. The client component verifies that the electronic information has not previously been sent to the client component. The client component generates and transmits a message to the server indicating the electronic information that has been previously sent to the client component. The server deletes electronic information that has been previously sent to the client component from the archive. The server compresses electronic information remaining in the archive into a streaming format and sends the electronic information to the client component. The electronic information is decompressed by the client component and provided to the user via the computer. The invention also includes related methods.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims earlier filing benefits of provisional application No. 60/121,099 filed Feb. 22, 1999 naming David Guthrie as the sole inventor. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to the delivery of data over a computer network, and more particularly, to the delivery of data that conforms to information about subscribers within the subscriber base.  
         BACKGROUND OF THE INVENTION  
         [0003]    Computer networks are known and used to deliver files and other aggregate forms of data to users over the network. As usage of the internet has grown, so has the number of sites where files and other aggregate forms of data are stored. To facilitate users being able to review and retrieve information from the various sites on the internet, search engines have been developed. Some search engines are publicly available such as those implemented at www.yahoo.com, www.excite.com and www.altavista.com. Using the search engines at these sites, the user may type in terms related to topics of interest to a user. The search engine then identifies various sites where files or other data related to the topics of interest are stored. The user then uses information about the various sites displayed by the search engine to determine which ones the viewer wants to “visit” to evaluate the site.  
           [0004]    While these publicly available search engines facilitate a user&#39;s identification of sites having information being sought by a user, they still require the user to conduct the search, review the results of the search and then conduct their own research on the various sites located by the search to locate information. In an effort to further facilitate a user&#39;s tasks to identify and retrieve data, agent programs have been developed that accept parameters identifying information of interest to a user. These agent programs then periodically conduct searches for data sites on the internet that have information related to the search parameters and collect relevant information from those identified sites. This information may then be downloaded to the user so the user may evaluate which information the user actually peruses.  
           [0005]    These agent programs do alleviate some of the tasks associated with a user conducting their own research over the internet. However, the management of the agent program still must be performed by the user. In addition, agent programs do not parse the retrieved data files to eliminate redundant articles and images. Consequently, the user may have to sort through an unnecessary amount of data. Also, if any of the files downloaded included data objects that require interaction with a user, the user must go to the site on the internet and interact with that file and data object as the agent program is usually unable to do so.  
           [0006]    What is needed is a system that does not need to be managed by a user but which provides information relevant to a user&#39;s needs on a periodic basis.  
           [0007]    What is needed is a system that eliminates redundant files and images corresponding to identified parameters for data of interest to a user before delivering the data to the user for review.  
           [0008]    What is needed is a system that permits a user to interact with data objects even though the data object is not being communicated during a session with a site from which the data object was retrieved.  
         SUMMARY OF THE INVENTION  
         [0009]    These and other limitations of previously known systems for retrieving data for users are overcome by a system and method of the present invention. The informational system of the present invention is comprised of a client component resident on a computer system at a user&#39;s computer and a server that collects electronic information corresponding to each user&#39;s customized profile for delivery to the client component. The information collected includes documents and images received from internet sites or it may include content from servers located at the server site facility. In one application of the present invention, the users are doctors and the content may include articles from medical publications addressing a doctor&#39;s practice specialty, information provided by sponsors for the informational system, and miscellaneous information of personal interest to a doctor. Documents and images from these various sources are retrieved and used to populate archives defined by a profile associated with an identified user for each client component in the system. Prior to delivering the contents collected for the archive, checksums identifying the articles and images within an archive are sent to the corresponding client component which verifies that an article or image has not been previously sent to the client. If the client sends a message to the server indicating that one or more articles or images have been previously transmitted to the client, those redundant elements are deleted from the archive. The remaining elements of the archive are then compressed in a streaming format and delivered to the client component. The downloaded archive is decompressed by the client component and provided to the user.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The accompanying drawings, which are incorporated and constitute a part of the specification, illustrate preferred and alternative embodiments of the present invention and, together with the general description given above and the detailed description of the embodiments given below, serve to explain the principle of the present invention.  
         [0011]    [0011]FIG. 1 is a block diagram of a system architecture incorporating the inventive system and method of the present invention; and  
         [0012]    [0012]FIG. 2 is a depiction of communications between a client and server implementing the system of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    The informational system of the present invention utilizes the Internet pipeline to deliver news and information to a user&#39;s desktops. Start to finish, the informational publishing system can be briefly summed up in the four-part diagram shown in FIG. 1.  
         [0014]    Content (Network—Automatic Content Feeds—Data Store—Internal Reporting)  
         [0015]    Content consists of everything the physician receives from the system, including specialty specific medical news, policy news, continuing medical education (CME), reference resources, financial, travel and lifestyle information.  
         [0016]    The Publishing Mechanism (Data Store—Edited Copy—Publishing Tools)  
         [0017]    The tools used to create, edit and ‘publish’ the content for a user. These include third-party applications for content creation, the Greenburg News Network (GNN) publishing tool Medcast Administrator, Continuing Medical Education test creation, and server side publishing.  
         [0018]    Internal Network Architecture (Oracle database—Load balancing/fault tolerance—HTTP server)  
         [0019]    This includes the hardware and software GNN uses to process, store, and deliver content to the end users.  
         [0020]    Physician&#39;Site (Medserver Proxy—Server)  
         [0021]    In a preferred embodiment, the users are physicians and the data content is targeted for physicians and their medical practices. The system discussed below is made with reference to this preferred embodiment. The terms ‘Medcast server’ and ‘Medcast client’ refer to the server and client components in this preferred embodiment. Details of the hardware and software used by the physicians and the manner in which they access Medcast content include a single-user set up with a modem; single user on a LAN with a wide area network; or multi-users on a Local Area Network (LAN) with a Medcast site server.  
         [0022]    All Medcast client software is developed using Microsoft&#39;s visual C++, due to its wide acceptance, speed, and array of Software Development Kits (SDKs). Additionally, the ability to cross compile this software is important for compatibility with future upgrades and products.  
         [0023]    All client software is 32-bit. This provides users of the inventive system with fast, flexible applications suitable for multi-tasking and multi-processing operating systems. The informational system of the present invention operates under Windows 95/98 and Windows NT operating systems, with twenty-four megabytes of RAM, though thirty-two is preferable.  
         [0024]    Site Configurations  
         [0025]    Single-user Set up with Modem  
         [0026]    A simple installation requiring software, hardware and configuration of an Internet Service Provider (ISP).  
         [0027]    Single-user on a Local Area Network with a WAN  
         [0028]    An installation of the software, configuration of ISP, and installation of hardware and Ethernet card for the LAN.  
         [0029]    Large multi-User installations on a LAN with a Medcast site server  
         [0030]    The proxy server of the present invention is Windows NT-based, which is designed to serve all Medcast subscribers on the LAN. Hardware for the proxy server consists of a 400 MHz Pentium with Ethernet, 64 Mb of RAM, tape backup, 4 Gb hard drive, 32x CD-ROM, 10/100 Ethernet Card, monitor, mouse and keyboard.  
         [0031]    The proxy software server system acts as a proxy to the Medcast Broadcast Center. It enables each local user to receive updates from the local proxy server instead of the Medcast Broadcast server. This reduces the overall bandwidth requirements on the local LAN&#39;s internet Connection and enables the local administrator to control the time of delivery and updates. It also provides the administrator controls for handling access to the proxy server.  
         [0032]    CLIENT SERVER COMMUNICATIONS  
         [0033]    To deliver updates to a physician&#39;s site, the system of the present invention uses the TCP/IP standard protocol with a standard Internet connection. Configurable updating routines are available, allowing physicians to update their systems in the middle of the night if they use Microsoft&#39;s PPP dialer with Windows 95/98 or NT. If a physician is on a direct connection she or he can receive numerous updates throughout the day. The basic update process is described with reference to FIG. 2:  
         [0034]    Authenticate  
         [0035]    Authentication happens before every action. User name and password given. Init.cgi sends information to the database and learns whether it&#39;s correct or not. (Or, to use an analogy, you&#39;ve just walked in the door of a restaurant.) 
         [0036]    1. Transmit log riles and content information (Analogy: you tell folks in the restaurant what you&#39;ve been doing since last you saw them.)  
         [0037]    2. Store log files and content information into the database (Analogy: your order number is generated.) Record session in queue (Analogy: your order number is given to you.)  
         [0038]    4. Return session ID and server time (Analogy: You order “A number five, please.”) Get queue information and content list (Analogy: the chef receives your order.)  
         [0039]    5. Get queue information and content list (Analogy: The chef receives your order.)  
         [0040]    6. Generate file list and custom files (Analogy: Gathering the ingredients for what you ordered.)  
         [0041]    7. Download list of files. This is a list of content identifiers the server thinks the client should have. (Analogy: on the server side this would consist of the entire recipe of what you just ordered. But what&#39;s sent to you, the client, is a stripped down version: instead of the ingredients of your order, you just see “A number five consists of: cheese burger, rhubarb pie, milk”  
         [0042]    8. Return optimized list. The client sends Hoark a list of files that the client doesn&#39;t require. (Analogy: You&#39;ve learned exactly what a number five is and decide you don&#39;t want the milk because you brought one with you, so you return a list of what you don&#39;t want.)  
         [0043]    9. Read files. Hoark reconstitutes what you&#39;ve sent back, being sure you didn&#39;t reject something that wasn&#39;t on the list of offerings. (Analogy: the chef makes sure you didn&#39;t reject something that didn&#39;t come with your order.)  
         [0044]    10. Download files. The files are downloaded. (Analogy: the dish is served.)  
         [0045]    11. Acknowledgment. The client indicates all the files were received and whether or not there was a problem, this session is done. (Analogy: Bye, great pie, I&#39;ll be back!) 
         [0046]    A more detailed breakdown of the client server communications follows:  
         [0047]    Authenticate  
         [0048]    Summary  
         [0049]    Every interaction between the client and the services available at the server is mediated by a web server. This mechanism provides authentication, logging, and (potentially) load balancing using a single, popular, off the shelf tool. It also obviates any network code in the server side elements (the CGIs).  
         [0050]    Every connection instance is authenticated using the standard “Basic Authentication” provided by the web server. Preferably, the authentication module which is integrated with an Apache web server and the module queries an Oracle database for authentication data. No data is transferred until authentication is successful.  
         [0051]    Once past this initial step the client and the server side (CGI) process are connected. The CGI process has access to the client user name (via the remote_user environment variable) and a communications stream via Standard  10 .  
         [0052]    Details  
         [0053]    The preferred authentication module used under Apache consults an Oracle database. It uses the popular “External Auth” module for Apache.  
         [0054]    Configuring the web server to use this authentication method is done using SetExtemalAuthMethod as:  
         [0055]    SetExternalAuthMethod GNNAUTH function  
         [0056]    Then for each table/column combination, an AddExternalAuth directive is added. The form of the directive is:  
         [0057]    AddExternalAuth GNNAUTH GNNAUTH:table,user_col,passwd_col,style where table is the Oracle table name, user_col is the column name of the username, and passwd_col is the column name of the password.  
         [0058]    Style should be one of “clear” for plaintext passwords or “des” for unix style 13 character passwords.  
         [0059]    If you use the special table name “oracle” then instead of checking an Oracle table, the given username and password is used to attempt to log into the Oracle database. If that works a “pass” is reported. (The other 3 arguments are ignored.) Transmit Log Files And Content Information  
         [0060]    Summary  
         [0061]    This is the first step performed by init.cgi. The article request data is sent to the cgi by the client, the size of which is determined by an HTTP header. This data is put into the database LOB store. Next, the client activity log is sent to the server, the size of which is also in an HTTP header, and saved to a file on the server&#39;s file system. These log files are to be gathered and parsed by a separate process.  
         [0062]    Details  
         [0063]    User Activity Log  
         [0064]    The Medcast client applications track the user&#39;s activity in a log file and transmit that log file to the Medcast server during each update. Once a log file has been transmitted, it is deleted from the client machine and a new log file is begun. The log file format is:  
                                                   USERNAME\tUID\tMACHINEID\n           ACTION CATEGORY\tACTION\n           ACTION CATEGORY\ACTION_ID\n                      
 
         [0065]    The file consists of an initial line identifying the user and the machine being used. The following lines identify the sequence of actions the user performed since the previous update.  
         [0066]    Action Categories  
         [0067]    Action categories describe the general action that was performed. The categories consist of:  
         [0068]    AD an ad played  
         [0069]    ARC saved an article to the archive  
         [0070]    ART an article was viewed  
         [0071]    BTN a button was pressed  
         [0072]    CHN the table of contents page for a channel was viewed via the channel selector or a channel://command  
         [0073]    ERR an error occurred  
         [0074]    Action Identifiers  
         [0075]    Action identifiers can have different meaning depending upon their associated action category.  
                                                           AD   the ID of the ad that was played; it is represented as &lt;AID&gt;.&lt;GID&gt;       ARC   the ID of the article that was archived;           it is represented as &lt;AID&gt;.&lt;GID&gt;       ART   the ID of the article that was viewed;           it is represented as &lt;AID&gt;.&lt;GID&gt;       BTN   the name of the button pressed;           (if the button simply pulls up a TOC page,           then the CHIN action is fired instead)                EMAIL           INTERNET           OPEN           FIND           CUSTOMIZE           DAILY (Daily Broadcast)           EVENT (Live Events)           SPONSOR (Sponsor Channels)            CHN   the ID of the channel whose TOC page was viewed;           It is represented as &lt;GID&gt;       ERR   an error type identifier followed by an           error message; valid error types are:           data an error in the databases; the accompanying error message will           contain a number identifying the specific error       otbx   an error with the outbox; the accompanying error message contains           some information about the offline form which failed to submit                  
 
         [0076]    Init.cgi returns a status  500  if it has an internal failure. All server errors are logged.  
         [0077]    Store Log Files And Content Information  
         [0078]    Summary  
         [0079]    This step happens pseudo-inline within init.cgi. The activity log data is streamed directly to a file as it is received. The article request information is stored in an intermediate buffer to be spooled to the server database. The LOB containing the article request contains ASCII data, as described above. This data is later interpreted by the MDAD process.  
         [0080]    Details  
         [0081]    See Appendix B, Step 4+for examples of input, output and init&#39;s code.  
         [0082]    Record Session In Queue  
         [0083]    Summary  
         [0084]    A new record is created in the download_queue table, populating the appropriate fields.  
         [0085]    Details  
         [0086]    The medcast_user_id, status, source_ip, queue_type fields are populated. The medcast_user_id is the user identification that the client uses to connect to the server, the status is set to the state of QUEUED as defined in download_queue states.h, the source_ip is passed from HTTP header information, and queue_type is set to ‘A’ or ‘M’ as gathered. from the HTTP_UPDATE_TYPE environment variable. See Appendix B for examples of input, output and init&#39;s code.  
         [0087]    Return Session ID and Server Time  
         [0088]    Summary  
         [0089]    The session_id assigned by the database to the newly inserted record in the download_queue table, is sent to the client along with the number of seconds elapsed on the server&#39;s clock since Jan. 1, 1970.  
         [0090]    Details  
         [0091]    These values are returned to the client as name=value pairs in the form of: 
         session_id=10859 
         time_t=902361932 
         [0092]    See Appendix B for examples of input, output and init&#39;s code.  
         [0093]    Get Queue Information and Content List  
         [0094]    This is a process request list which generates a list of articles and other lobs, plus a custom archives For more details, see “Tradecast client to server request” in Appendix B-2 and all of Appendix D.  
         [0095]    Generate File List and Custom Files See Appendix D for mdad information.  
         [0096]    Download List of Files  
         [0097]    Summary  
         [0098]    This step is performed by monkey.cgi. This list of files consists of a datum pair for each file, the pairs being an MDS checksum of the file as stored in the server database, and the length of the file. This list of datum pairs is compared against files stored in the client database and duplicates are removed. (See Appendix A for examples of input, output and monkey&#39;s code.)  
         [0099]    Details  
         [0100]    The monkey CGI return data is composed of:  
         [0101]    Header: any lines beginning with # are part of the header and treated as comments. The header may or may not contain useful information but at the least it contains the version of the data format, and a current Unix-style date ( 3 ) string.  
         [0102]    Data: provides a unique fingerprint for each file the server believes the client needs (the fingerprint consists of an MD5 checksum and a data length). The MD5 appears as a hexadecimal string 128 bits long, followed by a space, and then the long integral representation of the file&#39;s length as stored in the server database. The line is ended with the new line character ‘\n’.  
         [0103]    #Version: 1.0  
         [0104]    # Date: Jun. 22, 2001  
                               A                 fingerprint                 for                 every                 file                 that                 follows                 comes                 after                 the                 monkey     -     p                   header   .                   The                 fingerprint                 is                 the                 ASDII                 representation                 of                 a                 3                 2                 bit                 hex                 number                 representing                       the                 MD                 5                 checksum     ,     a                 space     ,     then                 the                 size                 of                 the                 file                 is                 represented                 in                 bytes                 in                       ASDII                   digits   .             }        monkey                 data                         
 
         [0105]    Monkey.cgi returns an HTTP status of  509  if the server isn&#39;t ready for the client, and a status  510  if the client requests bogus article information, or MDAD is unable to process the request data.  
         [0106]    Monkey.cgi returns a status  500  if it has an internal failure. All server errors are logged.  
         [0107]    Return Optimized List, Read Files, and Download Files are Combined and Explained in the Following  
         [0108]    Summary  
         [0109]    Hoark is the service which sends content to the client system. In a previous step, the system has generated a download offerings list based on client input. This information (or a derivative) is available both to the client and the server.  
         [0110]    Upon connection, the client transmits a selection of that list consisting of items which the client does not want downloaded (because it already has them locally). The server then transmits the remaining items from the original download offerings list.  
         [0111]    Details  
         [0112]    request phase: Client connects and sends a newline separated list of pointers into the offerings list (ASCII representation), followed by a blank line:  
         [0113]    3\n  
         [0114]    23\n  
         [0115]    9\n  
         [0116]    \n  
         [0117]    response phase: Server sends a stream of commands to a virtual machine within the client. The generic command format is:  
                                           tag (1 byte)   length of data in bytes   data (if any)           (32 bit unsigned integer)                  
 
         [0118]    All numeric data is transmitted in network byte order.  
         [0119]    Tag definitions:  
                                       Tag Symbol and transmitted   Data           value   Length   Dates and Notes                   END_CHANNEL(1)   4   single channel ID (32 bit unsigned integer) All               content associated with this channel has now               been transmitted.       ENCODING(2)   5   encoding_type (1 byte)               how_many (32 bit unsigned integer)               The next how_many bytes of the command               stream will be encoded according to               encoding_type. It is expected that zlib style               compression will be the most popular option.               Only one ENCODING is allowed at a time.       CONTENT(3)   ?   Data overwrites virtual machine content buffer       NO_CONTENT(4)   0   Effectively requests the client to load the virtual               machine content buffer using the content               associated with content_ID command. The               client should be able to do this because it was               listed as an item the client already has.       ARTICLE_INFO(5)   ?   Opaque article info, at least contains article and               channel id Write the content buffer as this article.       CONTENT_ID(6)   ?   MD5 sig and content length (ASCII               representation), separated by one space.               This command always immediately precedes the               content or no_content command which it&#39;s               associated with.       COMMENT(7)   ?   Comment text which may be logged by the               client.       END_OF_TRANSMISSION(9)   1   status (1 byte)               All done, server drops the connection               Nonzero status indicates error condition.       START_OF_TRANMISSION(9)   4   server_version (32 bit unsigned integer)               Must be first command sent to client.       SESSION_ITEMS(10)   4   The number of content and no-content tags to be               transmitted this session (a 32 bit unsigned               integer).               This command is optional and may appear               anywhere in the session stream.                  
 
         [0120]    Encoding and Compression:  
         [0121]    The idea with the table above is that after an ENCODING command, the next n bytes of the data stream are decoded.  
         [0122]    The client implementor writes a decoder atop whatever is reading the socket. This keeps track of the present encoding (if any) and returns uncompressed data to the client application.  
         [0123]    Acknowledgment  
         [0124]    See Appendix C for acknowledgment information.  
       APPENDIX A  
       [0125]    Appendix A: Monkey CGI  
         [0126]    The Monkey CGI is the second step in the download process. It performs several actions both in the database, with input data, and returning data.  
         [0127]    Monkey Process:  
         [0128]    1. Retrieve HTTP_SESSION_ID from the environment.  
         [0129]    2. Check to see if the user is active; disconnect if not.  
         [0130]    3. SELECT the status field FROM download_queue WHERE session_id matches HTTP_SESSION_ID  
         [0131]    4. If status ( as defined in download_queue_states.h ) is less than PROCESSED return: “Status:  509  Service not ready, try back later” “Retry-after: 30”and disconnect.  
         [0132]    5. Else if status=BOGUS return: “Status:  510  Invalid article request data” and disconnect.  
         [0133]    6. Else set status=MONKEYING and COMMIT database.  
         [0134]    7. Search mdad_article_listing for all records whose session_id field matches HTTP_SESSION_ID.  
         [0135]    8 Set crit field of each found record to the value of a sequentially updating counter, starting at 1.  
         [0136]    9. Using the gnnlob_id field value in the found record, find the matching record in the gnnlob table, and save the length and md5 checksum fields.  
         [0137]    10. Set status =MONKEYED in the download_queue record and COMMIT the database.  
         [0138]    11. Return header and list of md5/lengths (a newline separates these blocks)  
         [0139]    Monkey&#39;s Data:  
         [0140]    monkey.cgi uses two database tables, download_queue and mdad_article_listing. See comment in the CME section regarding these.  
         [0141]    The Input:  
         [0142]    HTTP Headers:  
         [0143]    HTTP_SESSION_ID—The session_id that the client was given by init.cgi.  
         [0144]    The Output:  
         [0145]    The Header:  
         [0146]    #Version: 1.0  
         [0147]    #Date: Wed Aug 5 16:33:29 EDT 1998  
         [0148]    The List:  
         [0149]    54c3057549c969358fe33e41d8a2a7fb 1056  
         [0150]    b43ca51181 a2a97615a06a42a7c1170 3545  
         [0151]    d382eca33fedba00cd24ff94f45bfa7a 1376  
         [0152]    b4e23ef9158f56b410417c29a08d0c11 29172  
         [0153]    [0153] 77 bb4d1578f8c64bla6ab8c4678b8409 4376 
         [0154]    The Code:  
         [0155]    This CGI is composed of the following files:  
                                                                                                                                                                                                                         monkey-cgi.cpp - Source file for CGI functions           monkey-db-funcs.pc - Source file for Oracle functions            monkey-cgi.cpp       This file contains the following functions:       take_a_pee - list the results for a user or all users       status_not_ready - return as status       indicating that the client&#39;s download_queue record isn&#39;t ready.       status_queue_failure -       return as status indicating that the client has requested bogus articles                take_a_pee                Declaration:                short take_a_pee(const list&lt;droplet&gt;&amp; droplets);                Arguments:                droplets - a linked-list of droplet structs.                Returns:                0 on success.           −1 on failure.           This function is very simple. It outputs a success           status, a header, and then           iterates over all items in droplets           outputting each item&#39;s md5 checksum           and length.                status_not_ready                Declaration:                void status_not_ready( );                Arguments:           Returns:                This function is called when it is determined           that the server is not ready           for the client to connect. It outputs an HTTP           status 509 and disconnects.                status_queue_failure                Declaration:                void status_queue_failure( )                Arguments:           Returns:                      
 
         [0156]    This function is called when it is determined that the client has requested bogus article. It outputs an HTTP status  510  and disconnects.  
         [0157]    monkey-db-funcs.pc  
         [0158]    This file contains the following functions:  
                                                                                               gather_droppings -       retrieve article information from the database for the client       gather_droppings                Declaration:                short gather_droppings(long session_id, list&lt;droplet&gt;&amp;droplets)                Arguments:                session_id - session_id given by the client.           droplets - empty list of droplet structs.                Returns:                0 on success.           −1 on failure.                      
 
         [0159]    This function is the checksum of the CGI. It performs all the checks described above, then queries the database for the md5 and length information that the client needs, and places them in a droplet struct, which is added to the droplets list.  
       APPENDIX B  
       [0160]    Appendix B: INIT CGI  
         [0161]    The Init CGI is the first step in the download process. It performs several actions both in the database, with input data, and returning data.  
         [0162]    1. Read REMOTE_USER, HTTP_COMPRESSED, HTTP_LOG_LENGTH, HTTP_ARTICLE_LENGTH, and LOG _PATH from the environment.  
         [0163]    2. Check the database for the state of the user. If they&#39;re inactive, drop the connection.  
         [0164]    3. Construct path to file to contain activity log data. This is in the form of:  
         [0165]    LOG_PATH[/]REMOTE_USER-&lt;time&gt;.log [.gz] where&lt;time&gt;is in the form of 21:34:28, and .gz is appended if HTTP_COMPRESSED is set to ‘Y’.  
         [0166]    4. Open the log output file.  
         [0167]    5. Read in HTTP_ARTICLE_LENGTH bytes of data to a buffer, to be stored in the database.  
         [0168]    6. Read in HTTP_LOG_LENGTH bytes of data to the log file opened above.  
         [0169]    7. Close the log file  
         [0170]    8. Read REMOTE_ADDR, REMOTE_USER, and HTTP_UPDATE_TYPE from the environment.  
         [0171]    9. INSERT INTO download_queue user_id, source ip, update type as REMOTE_USER, REMOTE_ADDR, HTTP_UPDATE_TYPE, retrieving the session_id of the new record, which is inserted automatically by a database trigger.  
         [0172]    10. INSERT the article request data buffer into the LOB store using the request_data column to save the gnnlob_id of the stored data.  
         [0173]    11. COMMIT the database.  
         [0174]    12. If successful, return the session_id and the value of time( NULL) to the client.  
         [0175]    The Input:  
         [0176]    HTTP Headers:  
         [0177]    Set by the HTTP server for all cgi&#39;s:  
         [0178]    remote_user—The id of the authenticated client user.  
         [0179]    remote_addr—The IP address of the client machine.  
         [0180]    Set by the HTTP server especially for init.cgi:  
         [0181]    LOG_PATH—Path to use for the saved activity log file.  
         [0182]    Set by the client when connecting:  
         [0183]    HTTP_COMPRESSED—Indicates if the activity log data is zlib compressed.  
         [0184]    HTTP_LOG_LENGTH—Length in bytes of the activity logo data.  
         [0185]    HTTP_ARTICLE_LENGTH—Length in bytes of the article request data.  
         [0186]    HTTP_UPDATE_TYPE—Values of ‘A’ or ‘M’ indicate automatic or manual download, respectively.  
         [0187]    1=inhouse; to staged content is downloaded. T=testing; mdad is being tested.  
         [0188]    Tradecast Client to Server Regitest/Article Request Data:  
         [0189]    Summary  
         [0190]    ARTICLES:71; 1+ 
         [0191]    ARTICLES:69; 1+ 
         [0192]    ADS_IN:75;  
         [0193]    ADS_IN:51  
         [0194]    ARTICLES:81; 1+ 
         [0195]    Details  
         [0196]    ARTICLE GROUP DOWNLOAD REQUEST  
                                                                                   ARTICLELIST_STR “:”&lt;gid&gt;“;”&lt;article limit&gt;&lt;article group list&gt;NL            &lt;gid&gt;   = group id       &lt;article limit&gt;   = “ ” | “&lt;”&lt;number&gt;“,”            (signifies that no more than ‘number’ articles should be downloaded)            &lt;article group list&gt;   = &lt;article&gt; “—” &lt;article&gt;       &lt;article group list&gt;   = &lt;article&gt;       &lt;article group list&gt;   = &lt;article group list&gt; “,” &lt;article&gt;       &lt;article group list&gt;   &lt;article&gt; “+”            where the plus ‘+’ signifies all articles &lt;= listed article       &lt;article group list&gt; = &lt;article group list&gt; “,” &lt;article&lt;“-”&lt;article&gt;       where the dash ‘-’ signifies a range of articles            N L   = “\n”            ARTICLELIST_STR = “ARTICLES”                  
 
         [0197]    (if no articles exist, request should be 1+)  
         [0198]    - - - “article limit” is being disabled as a feature  
         [0199]    ADS DOWNLOAD REQUEST  
                                                   ADSLIST_STR “:”&lt;gid&gt;“;”&lt;ad-list&lt;           &lt;ad&gt; = download id of ad           &lt;ad_list&gt; = “ ”           &lt;ad_fist&gt; = &lt;ad&gt;           &lt;ad_list&gt; = &lt;ad&gt;, &lt;ad-list&gt;           ADSLIST_STR = “ADS_IN”                      
 
         [0200]    where ad_list is all the ads for the given group.  
         [0201]    STOCKS DOWNLOAD REQUEST  
                                   STOCK_LIST_STR “:”&lt;5-letter-code-list&gt;NL       &lt;5-letter-code-list&gt; = 5-letter-code-list&gt;“,”&lt;5-letter-code&lt;       &lt;5-letter-code&gt; = code assigned by stock exchange (nyse, nysdex, etc)       ----‘JANSX’, etc (at most MAX_STOCKS per line)       STOCK_LIST_STR “STOCK”       NL = “\n”       MAX_STOCK = 25                  
 
         [0202]    Activity Log Data:  
                                                       BTN   CUSTOMIZE           BTN   FIND           BTN   CUSTOMIZE           BTN   CUSTOMIZE           BTN   FIND           BTN   CUSTOMIZE - Kevin           CHN   56           CHN   0           ART   1.1           CHN   7-09520           ART   1.1           CHN   0           ART   1.1           CHN   5118196           ART   1.1                      
 
         [0203]    The Output:  
         [0204]    The output consists of very simple name/value pairs. 
         session_id=1034587 
         time_t=902361932 
         [0205]    session_id is the value that the client should return when connecting to monkey.cgi, hoark.cgi, et. al. time_t is the value returned by calling time(NULL). It is used to determine what time the server thinks it is, so that the client and the server can be in sync.  
         [0206]    The Code:  
         [0207]    This CGI is composed of the following files:  
         [0208]    init_cgi.cpp—Source file for CGI functions init_db_funcs.pc—Source file for Oracle functions  
         [0209]    init-cgi.cpp  
         [0210]    This file contains the following functions:  
                                                                                                                                                                                       read_log_file - read the log file and request data in from the stream           print_output - return data to the client            read_log_file                Declaration:                short read_log_file(string &amp;request_data)                Arguments:                request_data -           string to be populated with the article request data from the           client.                Returns:                0 on success           −1 on failure           This function is designed to read in a specific           number of bytes of article           request data and a specific number of bytes of activity log data as           described above.            print_output                Declaration:                short print_output(long session_id)                Arguments:                session_id - session_id given by the client.                Returns:                0 on success.           −1 on failure.                      
 
         [0211]    This function returns to the client the session_id and time_t identifiers as described above.  
         [0212]    init-db-funcs.pc  
         [0213]    This file contains the following functions:  
                                                                                                                     add_dlq_record - insert a new record into the download_queue table            display_options                Declaration:                short add_dlq_record (long &amp;session_id,           const string &amp; request_data);                Arguments:                session_id - session_id given by the client.           request_data - contains the request date from the client.                Returns:                0 on success.           −1 on failure.                      
 
         [0214]    This function inserts a new record in to the download_queue table and adds the article request data from the client to the LOB store as described above.  
       APPENDIX C  
       [0215]    Appendix C: Catfish CGI  
         [0216]    Catfish is the last cgi called by the client and its purpose is to clean up download_queue and mdad_article_listing, custom info and request data.  
         [0217]    When:  
         [0218]    Download-queue status is:  
         [0219]    HOARKED or  
         [0220]    DELETING or  
         [0221]    BOGUS  
         [0222]    session_id exist in download_queue user_id is user_id for given session  
         [0223]    Protocol:  
         [0224]    client sends session_id as an HTTP header (SESSION_ID: session_id) such that Apache sets the environment variable  
         [0225]    HTTP_SESSION_ID. gets the user_id from the appache auth.  
         [0226]    Success:  
         [0227]    [0227] 200  status  
         [0228]    LAST_UPDATE: TIME TO BE RETURNED TO INIT ON NEXT UPDATE  
         [0229]    DAILY_UPDATES: list of times for client to do its next updates  
         [0230]    Errors:  
         [0231]    [0231] 503  unable to connect to database  
         [0232]    [0232] 507  unable to cleanup download queue  
         [0233]    [0233] 400  improper input  
         [0234]    /opt/gnn/bin/catfish.cgi.cron_cleanup calls  
         [0235]    opt/gnrn/download_htdocs/catfish/catfish.cgi.cron_cleanup  
         [0236]    /opt/gnn/download_htdocs/catfish/catfish.cgi.cron_cleanup  
         [0237]    sets env  
         [0238]    Cron cleanup:  
         [0239]    CATFISH_CLEANUP_TIMEOUT number of seconds since last mod to denote expired download queue item  
         [0240]    CATFISH_EXTRA_WHERE extra where clause for cleanup  
         [0241]    CATFISH_ALL just needs to be set  
         [0242]    HTTP_SESSION_ID CLEANUP_ALL  
         [0243]    GNN_DBUSER oracle user  
         [0244]    GNN_DBPASSWD password for the oracle user  
         [0245]    Basically calls catfish.cgi with CATFISH_ALL set and HTTP_SESSION_ID set to “CLEANUP ALL” and catfish will go through the download queue and get any items that have not been modified in the last X seconds where X is CATFISH_CLEANUP_TIMEOUT if set to the default (currently 1 day). Overrides catfish constraint that the queue time have one of the approved statuses.  
       APPENDIX D  
       [0246]    Appendix D: Catfish CGI  
         [0247]    Source files uniquely for mdad  
         [0248]    make_download_archive.c  
         [0249]    mdad_tmp_table.pc  
         [0250]    make_archives.c  
         [0251]    source files uniquely for mdad.runnerd  
         [0252]    mdad.runner.c  
         [0253]    Environment variables used by mdad and mdad.runnerd  
         [0254]    mdad path  
         [0255]    path to mdad for mdad.runnerd to run may be full or relative mdad.runnerd does not chdir.  
         [0256]    email_error_to  
         [0257]    address to send email errors to default “&lt;tradecast.server.error@GNNcast.net&gt;” 
         [0258]    gnn_dbname  
         [0259]    oracle sid  
         [0260]    medcast_download_spool  
         [0261]    spool directory for custom data  
         [0262]    debug_tmp_dir  
         [0263]    where to put tmp files  
         [0264]    Log Files  
         [0265]    mdad.runnerd  
         [0266]    $TC_LOG_DIR/make_archive. log—runtime log  
         [0267]    debug logs—latest.log is the latest log  
         [0268]    $ DEBUG_TMP_DIR/debug/download/mdad.runnerd.dir/*  
         [0269]    mdad  
         [0270]    $TC_LOG_DIR/mdad.log—runtime log  
         [0271]    debug logs—latest.log is the latest log  
         [0272]    $ DEBUG_TMP_DIR/debug/download/INSTANCE/mdad.dir/*  
         [0273]    $ DEBUG_TMP_DIR/debug/download/mdad.dir/*  
         [0274]    debugging log files may be eliminated by not compiling with HDEBUG defined  
         [0275]    USAGE: mdad.runnerd.csh [NUMBER] 
         [0276]    USAGE: mdad.runnnerd [NUMBER] 
         [0277]    NUMBER is the number of mdads to keep going. Default is one max, and is currently  64 . It is set by the number of members of the array mdad_kids in mdad.runner.c  
         [0278]    mdad.runnerd.csh  
         [0279]    is a shell script which sets some env variables and runs itself in the backgroup and keeps mdad.runnerd going. If mdad runnerd exits with an exit status of 0, mdad.runnerd.csh also exits with an error status of 0.  
         [0280]    mdad.runnerd  
         [0281]    is a compiled executable which keeps X mdads running where X is the first arg on the command line. 
         1&lt;=X&lt;=max mdad kids (currently 64) 
         [0282]    Email of Errors  
         [0283]    Every time a kid stops (dies/quits) mdad.runnerd restarts the kid, logs it, and sends email to mdad@gnncast.net if it has not sent email within the last X seconds (currently 300).  
         [0284]    If mdad.runnerd restarts X kids within Y seconds, and it&#39;s been more than Z seconds since it last sent email to alert. mdad. has problems @ GNNcast.net, it does so.  
         [0285]    Y is currently 15 minutes (15 * 60)  
         [0286]    Z is currently 20 minutes (20 * 60)  
         [0287]    X is currently 128 defined by the number of members of kwpq  
         [0288]    Signals  
         [0289]    hup—kills off all kids and executes itself  
         [0290]    term—kills off all kids and quits  
         [0291]    int—ditto  
         [0292]    quit—ignored  
         [0293]    Note  
         [0294]    opens the runtime logfile with an exclusive to write so only one mdad.runnerd may run at a time.  
         [0295]    Bugs  
         [0296]    does not kill off mdads still running when it starts  
         [0297]    USAGE: mdad [LOGFILE ID] [SLEEP SECONDS] 
         [0298]    logfile  
         [0299]    negative pid of parent do not try to open  
         [0300]    1 attempt to open runtime log file of mdad.runnerd exclusively for writing.  
         [0301]    sleep seconds  
         [0302]    number of seconds to do nothing between no items found in the queue.  
         [0303]    Plan of attack  
         [0304]    startup cleanup  
         [0305]    Looks for mdad_tmp_tables for the current host (application server) which needs to be cleaned up (dropped). Resets any download_queue time back to QUEUED ( 20 ) that are at PROCESSING ( 30 ) if the mdad_tmp_table which created them does not exist.  
         [0306]    Main Processing Loop Steps  
         [0307]    1. Finds first queue request in download queue, first request is first one by queue_type then by create time where queue type is sorted by:  
         [0308]    a. tc_dlqt_manual (‘M’)  
         [0309]    b. tc_dlqt_in_house (‘H’)  
         [0310]    c. tc_dlqt_automatic (‘A’)  
         [0311]    d. tc_dlqt_testing (T)  
         [0312]    2. Sets that status to PROCESSING ( 30 ) and fills in the mdad_tmp_table in the download_queue  
         [0313]    3. Calls process_article_requests to obtain the request data in a parsed format file. Currently this functionality is in imglue.so  
         [0314]    4. Sets up temp param files. This is some of the custom info, mostly about the articles/channels of which the client needs to know. See OW mdad processes request data for more info  
         [0315]    5. Processes request filling up mdad_article_listing and adding to param files and inserting custom info into the tcar archive (custom archive).  
         [0316]    6. Put the param files as the last items in the tcar archive.  
         [0317]    7. Set the status of the download_queue item to be processed.  
         [0318]    8. 7 goto 1.  
         [0319]    How mdad Processes Request Data  
         [0320]    1. Creates one or more SQL queries from the request list which adds the article global ids to the tmp table, and executes them. After the initial insertion of articles into the tmp table, a query is performed to add all the offspring (children, grandchildren, etc ) of all articles which are in the tmp table. Currently this is done in such a way that the article is only in the tmp table once. It may be more efficient to have this uniqueness performed in step 2.  
         [0321]    2. Takes all the lists of article global ids in the tmp table and adds them to the mdad_article_listing table, leaving only tcar_name and cnt+++to be filled in later.  
         [0322]    3. Runs through the mdad_article_listing table for this session, adding appropriate info to the param files for each article, and filling in the tcar_name column of the table.  
         [0323]    4. By looking at the last_update time, and decrementing it by a fixed amount, adds state info to the param files about deleted articles, channel mods.  
         [0324]    5. Examines the clients overall version and adds the appropriate items to the download list along with a script to tell the client what to do with the new version update files.