Teradata Call-Level Interface Version 2. Reference for Network-Attached Systems

Transcription

1 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems Release B A April 2009

2 The product or products described in this book are licensed products of Teradata Corporation or its affiliates. Teradata, BYNET, DBC/1012, DecisionCast, DecisionFlow, DecisionPoint, Eye logo design, InfoWise, Meta Warehouse, MyCommerce, SeeChain, SeeCommerce, SeeRisk, Teradata Decision Experts, Teradata Source Experts, WebAnalyst, and You ve Never Seen Your Business Like This Before are trademarks or registered trademarks of Teradata Corporation or its affiliates. Adaptec and SCSISelect are trademarks or registered trademarks of Adaptec, Inc. AMD Opteron and Opteron are trademarks of Advanced Micro Devices, Inc. BakBone and NetVault are trademarks or registered trademarks of BakBone Software, Inc. EMC, PowerPath, SRDF, and Symmetrix are registered trademarks of EMC Corporation. GoldenGate is a trademark of GoldenGate Software, Inc. Hewlett-Packard and HP are registered trademarks of Hewlett-Packard Company. Intel, Pentium, and XEON are registered trademarks of Intel Corporation. IBM, CICS, RACF, Tivoli, and z/os are registered trademarks of International Business Machines Corporation. Linux is a registered trademark of Linus Torvalds. LSI and Engenio are registered trademarks of LSI Corporation. Microsoft, Active Directory, Windows, Windows NT, and Windows Server are registered trademarks of Microsoft Corporation in the United States and other countries. Novell and SUSE are registered trademarks of Novell, Inc., in the United States and other countries. QLogic and SANbox are trademarks or registered trademarks of QLogic Corporation. SAS and SAS/C are trademarks or registered trademarks of SAS Institute Inc. SPARC is a registered trademark of SPARC International, Inc. Sun Microsystems, Solaris, Sun, and Sun Java are trademarks or registered trademarks of Sun Microsystems, Inc., in the United States and other countries. Symantec, NetBackup, and VERITAS are trademarks or registered trademarks of Symantec Corporation or its affiliates in the United States and other countries. Unicode is a collective membership mark and a service mark of Unicode, Inc. UNIX is a registered trademark of The Open Group in the United States and other countries. Other product and company names mentioned herein may be the trademarks of their respective owners. THE INFORMATION CONTAINED IN THIS DOCUMENT IS PROVIDED ON AN AS-IS BASIS, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF IMPLIED WARRANTIES, SO THE ABOVE EXCLUSION MAY NOT APPLY TO YOU. IN NO EVENT WILL TERADATA CORPORATION BE LIABLE FOR ANY INDIRECT, DIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS OR LOST SAVINGS, EVEN IF EXPRESSLY ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. The information contained in this document may contain references or cross-references to features, functions, products, or services that are not announced or available in your country. Such references do not imply that Teradata Corporation intends to announce such features, functions, products, or services in your country. Please consult your local Teradata Corporation representative for those features, functions, products, or services available in your country. Information contained in this document may contain technical inaccuracies or typographical errors. Information may be changed or updated without notice. Teradata Corporation may also make improvements or changes in the products or services described in this information at any time without notice. To maintain the quality of our products and services, we would like your comments on the accuracy, clarity, organization, and value of this document. Please teradata-books@lists.teradata.com Any comments or materials (collectively referred to as Feedback ) sent to Teradata Corporation will be deemed non-confidential. Teradata Corporation will have no obligation of any kind with respect to Feedback and will be free to use, reproduce, disclose, exhibit, display, transform, create derivative works of, and distribute the Feedback and derivative works thereof without limitation on a royalty-free basis. Further, Teradata Corporation will be free to use any ideas, concepts, know-how, or techniques contained in such Feedback for any purpose whatsoever, including developing, manufacturing, or marketing products or services incorporating Feedback. Copyright by Teradata Corporation. All Rights Reserved.

3 Preface Purpose This book provides information about Teradata Call-Level Interface Version 2 for Network- Attached Systems (CLIv2), which is a Teradata Tools and Utilities product. Teradata Tools and Utilities is a group of products designed to work with Teradata Database. CLIv2 is a library of routines that enable an application to access data on Teradata Database. Audience This book is intended for use by: System and application programmers responsible for writing programs to access data on a Teradata Database System administrators Database administrators Relational database developers Supported Releases This book supports the following: Teradata Database Teradata Tools and Utilities Teradata Call-Level Interface Version 2 for Network-Attached Systems Note: See The qepitem Field on page 218 for the query that verifies the version number. To locate detailed supported release information: 1 Go to 2 Click General Search under Online Publications.. 3 Type 3119 in the Publication Product ID box. 4 Under Sort By, select Date. 5 Click Search. 6 Open the version of the Teradata Tools and Utilities ##.# Supported Platforms and Product Versions spreadsheet associated with this release. Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 3

4 Preface Prerequisites The spreadsheet includes supported Teradata Database versions, platforms, and product release numbers. Prerequisites The following prerequisite knowledge is required for this product: Basic computer technology Database management systems Utilities that load and retrieve data Changes to This Book The following changes were made to this book in support of the current release. Changes are marked with change bars. For a complete list of changes to the product, see the Teradata Tools and Utilities Release Definition associated with this release. Date and Release April August Description Corrected Table, Sequential Order of the DBCAREA. Added a description of how to set maximum file size of copanomlog. See COPANOMLOG, NETRACE, THREADLOGGING, and THREADONOFF on page 59. Expanded the syntax of LDAP authentication for logons. See LDAP on page 76. Added a new field in DBCAREA that indicates the character set used to construct error messages. See Message Charset Used on page 120. Modified the behavior of user exit routines, so CLI now works with or without user exit routines. See Overview on page 377 and CLI2EXITLVL Environment Variable on page 383. Added the following queries to in the table labeled The qepitem Field on page 218: QEPISCS (46) QEPICCS (47) QEPIUS (48) QEPIDAP (49) QEPITSS (50) QEPILNS (51) 4 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

5 Preface Additional Information Date and Release Description Added support for periodic data types. See Common Parcel Fields on page 247. Clarified the impact of user-defined functions (UDFs), which use the ElictData, ElicitFile, and ElicitName parcels. See Communicating with Teradata Database on page 27 and Continuing a Teradata SQL Request on page 48. Additional Information Additional information that supports this product and Teradata Tools and Utilities is available at the web sites listed in the table that follows. In the table, mmyx represents the publication date of a manual, where mm is the month, y is the last digit of the year, and x is an internal publication code. Match the mmy of a related publication to the date on the cover of this book. This ensures that the publication selected supports the same release. Type of Information Description Access to Information Release overview Late information Use the Release Definition for the following information: Overview of all of the products in the release Information received too late to be included in the manuals Operating systems and Teradata Database versions that are certified to work with each product Version numbers of each product and the documentation for each product Information about available training and the support center 1 Go to 2 Click General Search under Online Publications. 3 In the Publication Product ID box, type Click Search. 5 Select the appropriate Release Definition from the search results. Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 5

6 Preface Additional Information Type of Information Description Access to Information Additional product information CD-ROM images Ordering information for manuals General information about Teradata Use the Teradata Information Products web site to view or download specific manuals that supply related or additional information to this manual. Access a link to a downloadable CD-ROM image of all customer documentation for this release. Customers are authorized to create CD-ROMs for their use from this image. Use the Teradata Information Products web site to order printed versions of manuals. The Teradata home page provides links to numerous sources of information about Teradata. Links include: Executive reports, case studies of customer experiences with Teradata, and thought leadership Technical information, solutions, and expert advice Press releases, mentions, and media resources 1 Go to 2 Click Data Warehousing under Online Publications, Browse by Category. 3 Do one of the following: For a list of Teradata Tools and Utilities documents, click Teradata Tools and Utilities, and then select an item under Releases or Products. Select a link to any of the data warehousing publications categories listed. Specific books related to Teradata Call-Level Interface Version 2 for Network-Attached Systems are as follows: Teradata Tools and Utilities Installation Guide for Microsoft Windows B mmyx Messages B mmyx Teradata Tools and Utilities Command Summary B mmyx 1 Go to 2 Click Data Warehousing under Online Publications, Browse by Category. 3 Click CD-ROM List and Images. 1 Go to 2 Click How to Order under Print & CD Publications 3 Follow the ordering instructions. 1 Go to Teradata.com. 2 Select a link. 6 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

7 Table of Contents Preface Purpose Audience Supported Releases Prerequisites Changes to This Book Additional Information Chapter 1: Introduction to CLI What is CLIv2? Supported Operating Systems Interface Overview CLI Data Structures Communicating with Teradata Database Large Objects Programs Executed within the Database Parallel Teradata Database Operations Multi-Statement Management Multi-Thread Management Multi-Session Management Common Routines Supporting CLI Using the DBCAREA Setting Alarms and Signals Handling Password Expiration Chapter 2: Session Operations Preparing to Use CLI Setting/Using the DBCAREA Options Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 7

8 Table of Contents Establishing a Session Executing Startup Requests Submitting a Request Fetching the Response Continuing a Teradata SQL Request Ending a Request Aborting a Transaction Aborting a Request Aborting a LOB Request: Example Aborting a Request: Example Terminating a Session Cleaning Up CLI Single Session Example Multiple Session Example Options Processing Chapter 3: CLI Files and Setup Finding CLI Files on the System CLI Environment Variables Chapter 4: System Parameter Block (SPB) Processing Using the COPLIB Variable System Parameter Block (SPB) File The clispb.dat Listing Overriding Values Values Used by CLI: Summary Chapter 5: DBCAREA DBCAREA Fields Allocating the DBCAREA Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

9 Table of Contents DBCAREA Security Mechanism Fields Network CLIv2 User Exits Supported Mechanisms Single Sign-On Legacy Considerations Integrity and Compatibility Other Mechanisms Determining Session Username Default Mechanism Handling Unicode Credential Processing DBCAREA: Field Descriptions Individual Field Descriptions: Alphabetical Listing Change Options Character Set Pointer Character Set Type Connect Wait Continuation Code Current Request Buffer Length Current Response Buffer Length Data Encryption Date Form DBC Level Dynamic Result Sets Allowed Extension Pointer Exempt Session from DBCHWAT Eyecatcher Fetch Data Pointer Fetch Data Pointer, Move Mode Fetch Data Pointer, Locate Mode Fetch Error Indicator Fetch Maximum Data Length Fetch Parcel Flavor Fetch Returned Data Length Function Input DBCpath Input Request Id Input Session Id Keep Response Language Conformance Language Id Locate Mode Logon Length Logon Pointer Logon Mechanism Data Length Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 9

10 Table of Contents Logon Mechanism Data Pointer Logon Mechanism Name Maximum Decimal Precision Maximum Number Of Sessions Maximum Parcel Message Area Length Message Area Pointer Message Charset Used Message Length Message Length Returned Message Return Code Message Text MTDP Received MTDP Sent Output DBC Session Id Output DBCpath Output Host Id Output Request Id Output Session Id Parcel Mode Fetch Positioning-action Positioning-statement-number Positioning-value Request Buffer Length Request Length Request Mode Request Pointer Request Processing Option Response Buffer Length Response Mode Return Code Return Identity Data Return Object Return Time Run Length Run Pointer Segment Data Statement-status Stored Procedure Return Result Tell About Delay Time Time Timing Precision Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

11 Table of Contents Time1 Status Time5 Status Token Total Length Transaction Semantics Two Response Buffers Use Presence Bits using-data-count Using Data Length Using Data Length Array Using Data Pointer Using Data Pointer Array Variable Length Fetch Variable Length Request Wait Across Crash Wait Across Delay Wait For Response Workload Length Workload Pointer DBCAREA Fields Not Used by Network-Attached Systems Chapter 6: DBCAREA Extensions Initiate-request Extensions Initiate-request Extensions Fields Connect extension (DBCACNX) Chapter 7: Common Routines Introduction Use Parameters DBCHINI DBCHCL DBCHCL Functions DBFCON DBFCRQ DBFRSUP Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 11

12 Table of Contents DBFIRQ DBFABT DBFFET DBFREW DBFERQ DBFDSC DBCHCLN Chapter 8: Other CLI Routines Use Parameters of CLI Routines: Tabular Summary DBCHFER DBCHFERL DBCHPEC DBCHQE DBCHREL DBCHSAD DBCHUE DBCHUEC DBCHWAT DBCHWL Chapter 9: Parcels Structure Parcel Types Request Parcels: Overview Response Parcels: Overview Common Parcel Fields Data Type Activity Type Parcel Descriptions Abort Abrt2PC Assign AssignRsp Cancel Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

13 Table of Contents Cmmt2PC Connect CursorDBC CursorHost Data DataInfo DataInfoX ElicitData ElicitDataReceived ElicitFile EndMultipartData EndMultipartIndicData EndMultipartRecord EndRequest EndStatement EndWith Error ErrorInformation ExtendedKeepRespond ExtendedRespond Failure Field Flagger FMReq FMRunStartup FormatEnd FormatStart IndicData IndicReq IVRunStartup KeepResp KeepRespond Logoff Logon MultipartData MultipartIndicData MultipartRecord MultipartRequest Multi-TSR NOP NullField OffsetPosition OK Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 13

14 Table of Contents Options PosEnd Position PosStart PrepInfo PrepInfoX RecEnd Record Record (In Indicator Mode) Record (In Record Mode) RecStart Req Resp Respond ResultSet ResultSet Cursor ResultSummary Rewind RowPosition Run RunResponse RunStartup SessionOptions Setposition Size SizeEnd SizeStart SP Options StatementInformation StatementInformationEnd Success TitleEnd TitleStart UserNameRequest UserNameResponse VoteRequest VoteTerm With Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

15 Table of Contents Chapter 10: Response Sequences The Request Buffer The Response Buffer The Move Area Typical Response Sequences Response Sequences: Field Mode Response Sequences: Indicator Mode Response Sequences: Multipart Indicator Mode Response Sequences: Record Mode Parcel Sequences Session Control: Logon Issuing Requests: Field Mode Issuing Requests: Indicator Mode Issuing Requests: Multipart Indicator Mode Issuing Requests: Record Mode Chapter 11: Return, Error, and Failure Codes Code Sources Return Code Values and Code Types Error and Failure Codes Responding to Error and Failure Parcels Checking Both Code Sources Chapter 12: Crash and Recovery Handling Crashes What the Teradata Database Does What MTDP Does AP Reset Containment (APRC) What the Application May Do Case 1: Tell and Wait Case 2: Just Wait Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 15

16 Table of Contents Case 3: Just Tell Chapter 13: Stored Procedures Introduction Description Send Procedure to Server Response Processing Abort, Cancel, and Restart Processing Effects on Other Options Chapter 14: Alternate Parcel Header Alternate Parcel Header Structure Client Interface Changes Using the New Element Structure Members of New Structure Elements Chapter 15: Extended Message Response Size Existing Scenario Limitation in extending the existing Scenario CLI - Client Interface changes Chapter 16: CLI Exit Functions Overview Use Parameters of CLI Exit Routines CliUsrLgnExt CLI Pre- and Post-Process SQL User Exits CliPreSQLExt Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

17 Table of Contents CliPostSQLExt User Exits for Security Level 2 Login and Pre & Post Exits CliLgnExit CliSQLExit CLI2EXITLVL Environment Variable Chapter 17: Large Objects (LOB) Support Introduction Determining LOB Support Inline Method Deferred Method Summary Error Messages and Codes Chapter 18: Performance Measurement Overview Appendix A: Examples of Using DBCAREA Extension Elements Sending TDSP Options Parcel Using 64-bit Implementation-Defined Extension Elements Sending TDSP Options Parcel Using APH Defined Extension Elements Sending a Parameterized SQL Using APH Defined Extension Elements Glossary Index Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 17

18 Table of Contents 18 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

19 List of Figures Figure 1: CLI Interface: Logical Structure Figure 2: CLI Routine Sequence Figure 3: Data Flow Figure 4: SPH Parcel Format Figure 5: APH Parcel Format Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 19

20 List of Figures 20 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

21 List of Tables Table 1: Single Session Sequence Table 2: Multiple Session Sequence Table 3: clispb.dat File Table 4: clispb.dat File Names Table 5: Mnemonic Names of Fields Table 6: Sequential Order of the DBCAREA Table 7: Processing Options for Network-Attached Systems Table 8: Uses of Routines and Functions Table 9: Parameters for CLI Routines Table 10: Function Abbreviations Table 11: Use of Routines Table 12: Parameters for CLI Routines Table 13: Parcel Flavors Table 14: Request Parcels Table 15: Response Parcels Table 16: Data Type Values Table 17: Activity Codes Table 18: PrepInfoX Data Types Table 19: Teradata Database Internal Format Table 20: ResultSummary Parcel Information Table 21: Full-layout Fields Table 22: PBTIFDT Additional Data Types Table 23: Limited-layout Fields Table 24: Statistic-layout Fields Table 25: Update Table1 Set Field1 = ; Table 26: Select Field1 From Table1; Table 27: Select Field1 From Table1 With Sum (FIELD1); Table 28: Select Field1 From Table1; Select Field2 From Table2; Table 29: Echo Select Field1 From Table1 ; Table 30: Update Table1 Set Field1 = ; Table 31: Select Field1 From Table1; Table 32: Select Field1 From Table1 With Sum (Field1); Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 21

22 List of Tables Table 33: Select Field1 From Table1; Select Field2 From Table2; Table 34: Echo Select Field1 From Table1 ; Table 35: Update Table1 Set Field1=999999; Table 36: Select Field1 From Table1; Table 37: Select Field1 from Table1 With Sum (Field1); Table 38: Select Field1 From Table1; Select Field2 From Table2; Table 39: Echo Select Field1 From Table1 ; Table 40: Error and Failure Codes Table 41: Parcel Headers Table 42: Use of Routines Table 43: CLI Routine Parameters Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

23 CHAPTER 1 Introduction to CLI This chapter describes the: CLIv2 interface, including its logical structure and the data structures supporting it Information flow between the application program and the Teradata Database using CLIv2 Common routines supporting CLIv2 Parallel processing capabilities of the Teradata Database, including multi-statement, multi-request, and multi-session management Setting of alarms and signals within a user s CLIv2 program and how password expiration is handled What is CLIv2? CLI Design Goals Teradata Call-Level Interface Version 2 for Network-Attached Systems (CLIv2, hereafter referred to as CLI unless otherwise noted), is a collection of callable service routines that provide the interface between applications and the Teradata Gateway. Gateway is the interface between CLI and the Teradata Database. CLI sends requests to the Teradata Database and provides the application with a response returned from the system. CLI provides support for: Managing multiple serially-executed requests on a session Managing multiple simultaneous sessions to the same, or different, Teradata Databases Using cooperative processing so that the application can perform operations on the client and the Teradata Database simultaneously Generally insulating the application from details in communicating with a Teradata Database The design of CLI was guided by the following goals: It must be simple to use. It must have enough power and flexibility to enable Teradata SQL (Structured Query Language) applications to exploit fully the power of the Teradata Database. It must be efficient. Workstation CPU and virtual storage utilization must be minimized. Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 23

24 Chapter 1: Introduction to CLI Supported Operating Systems The above goals must be met both for preprocessor applications and for applications that do not use a preprocessor, that is, for applications that make direct calls to CLI. It must support SQL/DS- and DB2- compatible preprocessors, if they become available. Installation and maintenance must be simple. Supported Operating Systems See Teradata Tools and Utilities xx.xx.xx Supported and Certified Versions B at For information about where CLI files are installed on different platforms, see Finding CLI Files on the System on page 57. Interface Overview Logical Structure Calling CLI Directly Applications manipulating data on the Teradata Database communicate indirectly with the Teradata Database by means of CLI. CLI is the interface between an application and the Micro Teradata Director Program (MTDP). CLI does the following: Builds parcels that MTDP packages for sending to the Teradata Database using the Micro Operating System Interface (MOSI), and Provides the application with a pointer to each of the parcels returned from the Teradata Database. MTDP is the interface between CLI and MOSI. MOSI is the interface to the Teradata Database. Applications coded in languages for which the Teradata Database does not provide a preprocessor, or applications requiring features not provided by the preprocessor, call CLI directly. But many applications use one of the Teradata SQL preprocessors and thus are shielded from the details of CLI. 24 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems

25 Chapter 1: Introduction to CLI CLI Data Structures Figure 1: CLI Interface: Logical Structure Application CLI Request MTDP Response MOSI Teradata Database 2418B004 CLI Data Structures CLI consists of the following data structures: Note: None of the following control blocks are available outside of CLI. DBCAREA and its extensions - Data Structure CLI2SPB - CLIv2 System Parameter Block CLI2ACB - CLIv2 Application Control Block CLI2SCB - CLIv2 Session Control Block CLI2RCB - CLIv2 Request Control Block MTDPCB - MTDP Control Block DBCAREA The DBCAREA is the communication structure between an application and CLI. Applications use it to forward control and data information. CLI uses it to return control and data information. Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems 25

26 Chapter 1: Introduction to CLI CLI Data Structures DBCAREA Extensions System Parameter Block Application Control Block Session Control Block Request Control Block MTDP Control Block An application may use a single DBCAREA or multiple DBCAREAs. CLI retains no knowledge of a particular DBCAREA across multiple CLI calls. CLI is concerned only with the values for DBCAREA that are meaningful to the routine called. A DBCAREA extension is addressed by a DBCAREA and allows specialized applications to provide additional information to CLI. The extensions may be chained together, allowing more than one extension for a single request. The CLI System Parameter Block (CLI2SPB), the internal SPB, is a data structure that is examined during initialization. During initialization, any DBCAREA values not set in the clispb.dat file by the user will default to the values contained in CLI2SPB. On the release media, the accessible SPB file is named clispb.dat and contains the required system-specific defaults when a DBCAREA is initialized. The values are specified with mnemonic field specifiers to permit flexible organization of data in the SPB file. The CLI Application Control Block (CLI2ACB) is an internal application-transparent area used to maintain the list of session control blocks (SCBs). As each SCB is created, it is inserted into the list of open SCBs pointed to by the ACB. The CLI Session Control Block (CLI2SCB) is an internal application-transparent area used to maintain the context of a session. When a logon is performed, an SCB is created to contain the session identifiers and the list of requests posted to the session, as well as the session state and associated information. The CLI Request Control Block (CLI2RCB) is an internal control block used to maintain the context of a request. When a request is posted to a session, an RCB is created to contain the request identifiers, the request state, and pointers to the request and response buffers associated with the request. The RCB is inserted in a queue of RCBs attached to a session s SCB. The MTDP Control Block (MTDPCB) is an internal data structure used by CLI to communicate with MTDP. Requested functions within MTDP, and information necessary to execute those functions, are communicated by the MTDP control block. 26 Teradata Call-Level Interface Version 2 Reference for Network-Attached Systems