V6.3-011 provides a way to recognize terminal disconnects, a larger database extension size and additional context for NOPRINCIO syslog messages. V6.3-011 also includes other fixes and enhancements. For more information, refer to the Change History section.

Items marked with document new or different capabilities.

Please pay special attention to the items marked with the symbols as those document items that have a possible impact on existing code, practice or process.

	Note
	Messages are not part of the GT.M API whose stability we strive to maintain. Make sure that you review any automated scripting that parses GT.M messages.

This document uses the following conventions:

	Note
	The term UNIX refers to the general sense of all platforms on which GT.M uses a POSIX API. As of this date, this includes: AIX and GNU/Linux on x86 (32- and 64-bits).

The following table summarizes the new and revised replication terminology and qualifiers.

Effective V6.0-000, GT.M documentation adopted IEC standard Prefixes for binary multiples. This document therefore uses prefixes Ki, Mi and Ti (e.g., 1MiB for 1,048,576 bytes). Over time, we'll update all GT.M documentation to this standard.

denotes a new feature that requires updating the manuals.

denotes a new feature or an enhancement that may not be upward compatible and may affect an existing application.

denotes deprecated messages.

denotes revised messages.

denotes added messages.

Over time, computing platforms evolve. Vendors obsolete hardware architectures. New versions of operating systems replace old ones. We at FIS continually evaluate platforms and versions of platforms that should be Supported for GT.M. In the table below, we document not only the ones that are currently Supported for this release, but also alert you to our future plans given the evolution of computing platforms. If you are an FIS customer, and these plans would cause you hardship, please contact your FIS account executive promptly to discuss your needs.

Each GT.M release is extensively tested by FIS on a set of specific versions of operating systems on specific hardware architectures (the combination of operating system and hardware architecture is referred to as a platform). This set of specific versions is considered Supported. There may be other versions of the same operating systems on which a GT.M release may not have been tested, but on which the FIS GT.M Group knows of no reason why GT.M would not work. This larger set of versions is considered Supportable. There is an even larger set of platforms on which GT.M may well run satisfactorily, but where the FIS GT.M team lacks the knowledge to determine whether GT.M is Supportable. These are considered Unsupported. Contact FIS GT.M Support with inquiries about your preferred platform.

As of the publication date, FIS supports this release on the hardware and operating system versions below. Contact FIS for a current list of Supported platforms. The reference implementation of the encryption plugin has its own additional requirements, should you opt to use it as included with GT.M.

The same application code runs on both 32-bit and 64-bit platforms; however there are operational differences between them (for example, auto-relink and the ability to use GT.M object code from shared libraries exist only on 64-bit platforms). Please note that:

Call-ins and External Calls

Parameter type	32-Bit	64-bit	Remarks
gtm_long_t	4-byte (32-bit)	8-byte (64-bit)	gtm_long_t is much the same as the C language long type.
gtm_ulong_t	4-byte	8-byte	gtm_ulong_t is much the same as the C language unsigned long type.
gtm_int_t	4-byte	4-byte	gtm_int_t has 32-bit length on all platforms.
gtm_uint_t	4-byte	4-byte	gtm_uint_t has 32-bit length on all platforms

	Caution
	If your interface uses gtm_long_t or gtm_ulong_t types but your interface code uses int or signed int types, failure to revise the types so they match on a 64-bit platform will cause the code to fail in unpleasant, potentially dangerous, and hard to diagnose ways.

Internationalization (Collation)

Parameter type	32-Bit	64-bit	Remarks
gtm_descriptor in gtm_descript.h	4-byte	8-byte	Although it is only the address within these types that changes, the structures may grow by up to 8 bytes as a result of compiler padding to meet platform alignment requirements.

	Important
	Assuming other aspects of code are 64-bit capable, collation routines should require only recompilation.

Environment Translation

Parameter type	32-Bit	64-bit	Remarks
gtm_string_t type in gtmxc_types.h	4-byte	8-byte	Although it is only the address within these types that changes, the structures may grow by up to 8 bytes as a result of compiler padding to meet platform alignment requirements.

	Important
	Assuming other aspects of code are 64-bit capable, environment translation routines should require only recompilation.

To install GT.M, see the "Installing GT.M" section in the GT.M Administration and Operations Guide. For minimal down time, upgrade a current replicating instance and restart replication. Once that replicating instance is current, switch it to become the originating instance. Upgrade the prior originating instance to become a replicating instance, and perform a switchover when you want it to resume an originating primary role.

	Caution
	Never replace the binary image on disk of any executable file while it is in use by an active process. It may lead to unpredictable results. Depending on the operating system, these results include but are not limited to denial of service (that is, system lockup) and damage to files that these processes have open (that is, database structural damage).

The GT.M database consists of four types of components- database files, journal files, global directories, and replication instance files. The format of some database components differs for 32-bit and 64-bit GT.M releases for the x86 GNU/Linux platform.

GT.M upgrade procedure for V6.3-011 consists of 5 stages:

Read the upgrade instructions of each stage carefully. Your upgrade procedure for GT.M V6.3-011 depends on your GT.M upgrade history and your current version.

Stage 2: Database Files Upgrade

Before starting the database file upgrade, use the prior GT.M version to perform an appropriate MUPIP action to removes abandoned GT.M database semaphores and releases any IPC resources.

To upgrade from GT.M V6*:

There is no explicit procedure to upgrade a V6 database file when upgrading to a newer V6 version. After upgrading the Global Directory, opening a V6 database with a newer V6 GT.M process automatically upgrades the fields in the database file header.

To upgrade from GT.M V5.0*/V5.1*/V5.2*/V5.3*/V5.4*/V5.5:

A V6 database file is a superset of a V5 database file and has potentially longer keys and records. Therefore, upgrading a database file requires no explicit procedure. After upgrading the Global Directory, opening a V5 database with a V6 process automatically upgrades fields in the database fileheader.

A database created with V6 supports up to 992Mi blocks and is not backward compatible. V6 databases that take advantage of V6 limits on key size and records size cannot be downgraded. Use MUPIP DOWNGRADE -VERSION=V5 to downgrade a V6 database back to V5 format provided it meets the database downgrade requirements. For more information on downgrading a database, refer to Downgrading to V5 or V4.

Important

A V5 database that has been automatically upgraded to V6 can perform all GT.M V6.3-011 operations. However, that database can only grow to the maximum size of the version in which it was originally created. A database created on V5.0-000 through V5.3-003 has maximum size of 128Mi blocks. A database created on V5.4-000 through V5.5-000 has a maximum size of 224Mi blocks. A database file created with V6.0-000 (or above) can grow up to a maximum of 992Mi blocks. This means that, for example, the maximum size of a V6 database file having 8KiB block size is 7936GiB (8KiB*992Mi).

	Important
	In order to perform a database downgrade you must perform a MUPIP INTEG -NOONLINE. If the duration of the MUPIP INTEG exceeds the time allotted for an upgrade you should rely on a rolling upgrade scheme using replication.

If your database has any previously used but free blocks from an earlier upgrade cycle (V4 to V5), you may need to execute the MUPIP REORG -UPGRADE command. If you have already executed the MUPIP REORG -UPGRADE command in a version prior to V5.3-003 and if subsequent versions cannot determine whether MUPIP REORG -UPGRADE performed all required actions, it sends warnings to the syslog requesting another run of MUPIP REORG -UPGRADE. In that case, perform any one of the following steps:

• Execute the MUPIP REORG -UPGRADE command again, or

• Execute the DSE CHANGE -FILEHEADER -FULLY_UPGRADED=1 command to stop the warnings.

	Caution
	Do not run the DSE CHANGE -FILEHEADER -FULLY_UPGRADED=1 command unless you are absolutely sure of having previously run a MUPIP REORG -UPGRADE from V5.3-003 or later. An inappropriate DSE CHANGE -FILEHEADE -FULLY_UPGRADED=1 may lead to database integrity issues.

You do not need to run MUPIP REORG -UPGRADE on:

• A database that was created by a V5 MUPIP CREATE

• A database that has been completely processed by a MUPIP REORG -UPGRADE from V5.3-003 or later.

For additional upgrade considerations, refer to Database Compatibility Notes.

To upgrade from a GT.M version prior to V5.000:

You need to upgrade your database files only when there is a block format upgrade from V4 to V5. However, some versions, for example, database files which have been initially been created with V4 (and subsequently upgraded to a V5 format) may additionally need a MUPIP REORG -UPGRADE operation to upgrade previously used but free blocks that may have been missed by earlier upgrade tools.

• Upgrade your database files using in-place or traditional database upgrade procedure depending on your situation. For more information on in-place/traditional database upgrade, see Database Migration Technical Bulletin.

• Run the MUPIP REORG -UPGRADE command. This command upgrades all V4 blocks to V5 format.

	Note
	Databases created with GT.M releases prior to V5.0-000 and upgraded to a V5 format retain the maximum size limit of 64Mi (67,108,864) blocks.

Database Compatibility Notes

• Changes to the database file header may occur in any release. GT.M automatically upgrades database file headers as needed. Any changes to database file headers are upward and downward compatible within a major database release number, that is, although processes from only one GT.M release can access a database file at any given time, processes running different GT.M releases with the same major release number can access a database file at different times.

• Databases created with V5.3-004 through V5.5-000 can grow to a maximum size of 224Mi (234,881,024) blocks. This means, for example, that with an 8KiB block size, the maximum database file size is 1,792GiB; this is effectively the size of a single global variable that has a region to itself and does not itself span regions; a database consists of any number of global variables. A database created with GT.M versions V5.0-000 through V5.3-003 can be upgraded with MUPIP UPGRADE to increase the limit on database file size from 128Mi to 224Mi blocks.

• Databases created with V5.0-000 through V5.3-003 have a maximum size of 128Mi (134, 217,728) blocks. GT.M versions V5.0-000 through V5.3-003 can access databases created with V5.3-004 and later as long as they remain within a 128Mi block limit.

• Database created with V6.0-000 or above have a maximum size of 1,040,187,392(992Mi) blocks.

• For information on downgrading a database upgraded from V6 to V5, refer to: Downgrading to V5 or V4.

Stage 3: Replication Instance File Upgrade

V6.3-011 does not require new replication instance files if you are upgrading from V5.5-000. However, V6.3-011 requires new replication instance files if you are upgrading from any version prior to V5.5-000. Instructions for creating new replication instance files are in the Database Replication chapter of the GT.M Administration and Operations Guide. Shut down all Receiver Servers on other instances that are to receive updates from this instance, shut down this instance Source Server(s), recreate the instance file, restart the Source Server(s) and then restart any Receiver Server for this instance with the -UPDATERESYNC qualifier.

Note

Without the -UPDATERESYNC qualifier, the replicating instance synchronizes with the originating instance using state information from both instances and potentially rolling back information on the replicating instance. The -UPDATERESYNC qualifier declares the replicating instance to be in a wholesome state matching some prior (or current) state of the originating instance; it causes MUPIP to update the information in the replication instance file of the originating instance and not modify information currently in the database on the replicating instance. After this command, the replicating instance catches up to the originating instance starting from its own current state. Use -UPDATERESYNC only when you are absolutely certain that the replicating instance database was shut down normally with no errors, or appropriately copied from another instance with no errors.

	Important
	You must always follow the steps described in the Database Replication chapter of the GT.M Administration and Operations Guide when migrating from a logical dual site (LDS) configuration to an LMS configuration, even if you are not changing GT.M releases.

Stage 4: Journal Files Upgrade

On every GT.M upgrade:

• Create a fresh backup of your database.

• Generate new journal files (without back-links).

	Important
	This is necessary because MUPIP JOURNAL cannot use journal files from a release other than its own for RECOVER, ROLLBACK, or EXTRACT.

Stage 5: Trigger Definitions Upgrade

If you are upgrading from V5.4-002A/V5.4-002B/V5.5-000 to V6.3-011 and you have database triggers defined in V6.2-000 or earlier, you need to ensure that your trigger definitions are wholesome in the older version and then run MUPIP TRIGGER -UPGRADE. If you have doubts about the wholesomeness of the trigger definitions in the old version use the instructions below to capture the definitions delete them in the old version (-*), run MUPIP TRIGGER -UPGRADE in V6.3-011 and then reload them as described below.

You need to extract and reload your trigger definitions only if you are upgrading from V5.4-000/V5.4-000A/V5.4-001 to V6.3-011 or if you find your prior version trigger definitions have problems. For versions V5.4-000/V5.4-000A/V5.4-001 this is necessary because multi-line XECUTEs for triggers require a different internal storage format for triggers which makes triggers created in V5.4-000/V5.4-000A/V5.4-001 incompatible with V5.4-002/V5.4-002A/V5.4-002B/V5.5-000/V6.0-000/V6.0-001/V6.3-011.

To extract and reapply the trigger definitions on V6.3-011 using MUPIP TRIGGER:

1. Using the old version, execute a command like mupip trigger -select="*" trigger_defs.trg. Now, the output file trigger_defs.trg contains all trigger definitions.

2. Place -* at the beginning of the trigger_defs.trg file to remove the old trigger definitions.

3. Using V6.3-011, run mupip trigger -triggerfile=trigger_defs.trg to reload your trigger definitions.

To extract and reload trigger definitions on a V6.3-011 replicating instance using $ZTRIGGER():

1. Shut down the instance using the old version of GT.M.

2. Execute a command like mumps -run %XCMD 'i $ztrigger("select")' > trigger_defs.trg . Now, the output file trigger_defs.trg contains all trigger definitions.

3. Turn off replication on all regions.

4. Run mumps -run %XCMD 'i $ztrigger("item","-*") to remove the old trigger definitions.

5. Perform the upgrade procedure applicable for V6.3-011.

6. Run mumps -run %XCMD 'if $ztrigger("file","trigger_defs.trg")' to reapply your trigger definitions.

7. Turn replication on.

8. Connect to the originating instance.

	Note
	Reloading triggers renumbers automatically generated trigger names.

MUPIP DOWNGRADE -VERSION=[V5|V4] 

With International Components for Unicode (ICU) version 3.6 or later installed, GT.M's UTF-8 mode provides support for Unicode® (ISO/IEC-10646) character strings. On a system that does not have ICU 3.6 or later installed, GT.M only supports M mode.

On a system that has ICU installed, GT.M optionally installs support for both M mode and UTF-8 mode, including a utf8 subdirectory of the directory where GT.M is installed. From the same source file, depending upon the value of the environment variable gtm_chset, the GT.M compiler generates an object file either for M mode or UTF-8 mode. GT.M generates a new object file when it finds both a source and an object file, and the object predates the source file and was generated with the same setting of $gtm_chset/$ZCHset. A GT.M process generates an error if it encounters an object file generated with a different setting of $gtm_chset/$ZCHset than that processes' current value.

Always generate an M object module with a value of $gtm_chset/$ZCHset matching the value processes executing that module will have. As the GT.M installation itself contains utility programs written in M, their object files also conform to this rule. In order to use utility programs in both M mode and UTF-8 mode, the GT.M installation ensures that both M and UTF-8 versions of object modules exist, the latter in the utf8 subdirectory. This technique of segregating the object modules by their compilation mode prevents both frequent recompiles and errors in installations where both modes are in use. If your installation uses both modes, consider a similar pattern for structuring application object code repositories.

GT.M is installed in a parent directory and a utf8 subdirectory as follows:

For more information on gtmprofile, refer to the Basic Operations chapter of GT.M Administration and Operations Guide.

Although GT.M uses ICU for UTF-8 operation, ICU is not FIS software and FIS does not support ICU.

The environment variable TERM must specify a terminfo entry that accurately matches the terminal (or terminal emulator) settings. Refer to the terminfo man pages for more information on the terminal settings of the platform where GT.M needs to run.

GT.M sends keypad_xmit before terminal reads for direct mode and READs (other than READ *) if EDITING is enabled. GT.M sends keypad_local after these terminal reads.

If you plan to use the optional compression facility for replication, you must provide the compression library. The GT.M interface for compression libraries accepts the zlib compression libraries without any need for adaptation. These libraries are included in many UNIX distributions and are downloadable from the zlib home page. If you prefer to use other compression libraries, you need to configure or adapt them to provide the same API as that provided by zlib.

If a package for zlib is available with your operating system, FIS suggests that you use it rather than building your own.

By default, GT.M searches for the libz.so shared library in the standard system library directories (for example, /usr/lib, /usr/local/lib, /usr/local/lib64). If the shared library is installed in a non-standard location, before starting replication, you must ensure that the environment variable LIBPATH (AIX) or LD_LIBRARY_PATH (GNU/Linux) includes the directory containing the library. The Source and Receiver Server link the shared library at runtime. If this fails for any reason (such as file not found, or insufficient authorization), the replication logic logs a DLLNOOPEN error and continues with no compression.

Although GT.M uses a library such as zlib for compression, such libraries are not FIS software and FIS does not support any compression libraries.

Fixes and enhancements specific to V6.3-011:

NOPRINCIO, Unable to dddd principal device: DDDD at LLLL due to: SSSS

Run Time Fatal: This indicates that GT.M attempted to, but could not, READ from, or WRITE to (direction indicated by dddd), the PRINCIPAL device, and therefore attempted to issue an appropriate error, for example, an IOEOF, TERMHANGUP, or TERMWRITE at location LLLL, with a status of SSSS. However, if the error handling does not prevent any and all subsequent READs and WRITEs to the no longer available PRINCIPAL device, the next subsequent I/O error shuts down the process immediately to prevent mysteriously lost output, or, worse, an indefinite loop. The NOPRINCIO message appears in the operator log

Action: The NOPRINCIO error message is FATAL which does not drive device or trap handlers and terminates the process. This termination does not allow any application level orderly shutdown and, depending on the application, may lead to out-of-design application state. Therefore FIS recommends appropriate application level error handling that recognizes the preceding error and performs an orderly shutdown without issuing any additional READ or WRITE to the principal device. The most common causes for the principal device to cease to exist involve terminal sessions or socket connections (including those from processes started by inetd/xinetd). When the remote client terminates the connection, the underlying PRINCIPAL device becomes inaccessible making any subsequent attempt to READ from, or WRITE to, it hopeless. In the case of terminals, a user closing the window of a session without cleanly exiting from the GT.M process sets up the case that can drive this error. GT.M does not issue NOPRINCIO errors from Direct Mode, because it is a developer tool, or at the completion a HEREDOC in a shell script. However, this means a HEREDOC must use ZHALT to return a specific status to the shell, and that a $ETRAP that bounces a process into Direct Mode terminates without evidence.

TERMHANGUP, Terminal has disconnected

Run Time Error: This indicates that the terminal serving as the PRINCIPAL device has disconnected. By default, GT.M ignores terminal "hang-ups," which can allow the terminal to reconnect at a later time to a process that does not need the terminal to continue work. You can enable recognition of Principal device disconnects with USE $PRINCIPAL:HUPENABLE or by starting the process with the gtm_hupenable set to 1, TRUE or YES, or disable them with USE $PRINCIPAL:NOHUPENABLE.

Action: When a process receives this error it must avoid any further READs from, or WRITEs to, $PRINCIPAL, typically by shutting down in a wholesome fashion. Failure to do so causes GT.M to terminate the process with a NOPRINCIO message to the operator log.

TRANS2BIG, Transaction exceeded available buffer space for region rrrr

Run Time Error: This indicates that a transaction updated more blocks than the global buffers could hold (half - 2) for a particular region rrrr or accessed more than the single transaction limit of 64Ki blocks.

Action: Look for missing TCOMMIT commands; modify the code to reduce the total content or change content of the transaction. If the transaction is as intended and the issue is the number of updates, increase the GLOBAL_BUFFERS for the region using MUPIP SET, or modify the Global Directory to redistribute the relevant globals to more regions. If this occurs on a replicating instance it may indicate either a difference in configuration between the originating and replicating instances, which probably should be addressed, or a transaction that was borderline on the originating instance, but failed on the replicating instance because of difference in the database layout. In the later case, consider examining the application code to see if it's possible to reduce the size of the transaction, or alternatively increase the global buffers on both the instances.