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Diffstat (limited to 'src/H5FDsubfiling/H5FDsubfiling.h')
| -rw-r--r-- | src/H5FDsubfiling/H5FDsubfiling.h | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/src/H5FDsubfiling/H5FDsubfiling.h b/src/H5FDsubfiling/H5FDsubfiling.h new file mode 100644 index 0000000..22dd906 --- /dev/null +++ b/src/H5FDsubfiling/H5FDsubfiling.h @@ -0,0 +1,384 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * Copyright by The HDF Group. * + * All rights reserved. * + * * + * This file is part of HDF5. The full HDF5 copyright notice, including * + * terms governing use, modification, and redistribution, is contained in * + * the COPYING file, which can be found at the root of the source code * + * distribution tree, or in https://www.hdfgroup.org/licenses. * + * If you do not have access to either file, you may request a copy from * + * help@hdfgroup.org. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* Purpose: The public header file for the subfiling driver. */ +#ifndef H5FDsubfiling_H +#define H5FDsubfiling_H + +#ifdef H5_HAVE_SUBFILING_VFD +/** + * \def H5FD_SUBFILING + * Macro that returns the identifier for the #H5FD_SUBFILING driver. \hid_t{file driver} + */ +#define H5FD_SUBFILING (H5FDperform_init(H5FD_subfiling_init)) +#else +#define H5FD_SUBFILING (H5I_INVALID_HID) +#endif + +/** + * \def H5FD_SUBFILING_NAME + * The canonical name for the #H5FD_SUBFILING driver + */ +#define H5FD_SUBFILING_NAME "subfiling" + +#ifdef H5_HAVE_SUBFILING_VFD + +#ifndef H5FD_SUBFILING_FAPL_MAGIC +/** + * \def H5FD_SUBFILING_CURR_FAPL_VERSION + * The version number of the H5FD_subfiling_config_t configuration + * structure for the #H5FD_SUBFILING driver + */ +#define H5FD_SUBFILING_CURR_FAPL_VERSION 1 +/** + * \def H5FD_SUBFILING_FAPL_MAGIC + * Unique number used to distinguish the #H5FD_SUBFILING driver from other HDF5 file drivers + */ +#define H5FD_SUBFILING_FAPL_MAGIC 0xFED01331 +#endif + +/** + * \def H5FD_SUBFILING_DEFAULT_STRIPE_SIZE + * The default stripe size (in bytes) for data stripes in subfiles + */ +#define H5FD_SUBFILING_DEFAULT_STRIPE_SIZE (32 * 1024 * 1024) + +/** + * \def H5FD_SUBFILING_DEFAULT_STRIPE_COUNT + * Macro for the default Subfiling stripe count value. The default + * is currently to use one subfile per node. + */ +#define H5FD_SUBFILING_DEFAULT_STRIPE_COUNT -1 + +/** + * \def H5FD_SUBFILING_FILENAME_TEMPLATE + * The basic template for a subfile filename. The format specifiers + * correspond to: + * + * %s -> base filename, e.g. "file.h5" + * %PRIu64 -> file inode, e.g. 11273556 + * %0*d -> number (starting at 1) signifying the Nth (out of total + * number of subfiles) subfile. Zero-padded according + * to the number of digits in the number of subfiles + * (calculated by log10(num_subfiles) + 1) + * %d -> number of subfiles + * + * yielding filenames such as: + * + * file.h5.subfile_11273556_01_of_10 + * file.h5.subfile_11273556_02_of_10 + * file.h5.subfile_11273556_10_of_10 + */ +#define H5FD_SUBFILING_FILENAME_TEMPLATE "%s.subfile_%" PRIu64 "_%0*d_of_%d" + +/** + * \def H5FD_SUBFILING_CONFIG_FILENAME_TEMPLATE + * The basic template for a #H5FD_SUBFILING driver configuration filename. + * The format specifiers correspond to: + * + * %s -> base filename, e.g. "file.h5" + * %PRIu64 -> file inode, e.g. 11273556 + * + * yielding a filename such as: + * + * file.h5.subfile_11273556.config + */ +#define H5FD_SUBFILING_CONFIG_FILENAME_TEMPLATE "%s.subfile_%" PRIu64 ".config" + +/* + * Environment variables interpreted by the HDF5 Subfiling feature + */ + +/** + * \def H5FD_SUBFILING_STRIPE_SIZE + * Macro for name of the environment variable that specifies the size + * (in bytes) for data stripes in subfiles + * + * The value set for this environment variable is interpreted as a + * long long value and must be > 0. + */ +#define H5FD_SUBFILING_STRIPE_SIZE "H5FD_SUBFILING_STRIPE_SIZE" +/** + * \def H5FD_SUBFILING_IOC_PER_NODE + * Macro for name of the environment variable that specifies the number + * of MPI ranks per node to use as I/O concentrators + * + * The value set for this environment variable is interpreted as a + * long value and must be > 0. + */ +#define H5FD_SUBFILING_IOC_PER_NODE "H5FD_SUBFILING_IOC_PER_NODE" +/** + * \def H5FD_SUBFILING_IOC_SELECTION_CRITERIA + * Macro for name of the environment variable that provides information + * for selection MPI ranks as I/O concentrators + * + * The value set for this environment variable is interpreted differently, + * depending on the IOC selection method chosen. + * + * For #SELECT_IOC_ONE_PER_NODE, this value is ignored. + * + * For #SELECT_IOC_EVERY_NTH_RANK, this value is interpreted as a + * long value and must be > 0. The value will correspond to the + * `N` value when selecting every `N`-th MPI rank as an I/O + * concentrator. + * + * For #SELECT_IOC_WITH_CONFIG, this value is ignored as that particular + * IOC selection method is not currently supported. + * + * For #SELECT_IOC_TOTAL, this value is interpreted as a long value + * and must be > 0. The value will correspond to the total number + * of I/O concentrators to be used. + */ +#define H5FD_SUBFILING_IOC_SELECTION_CRITERIA "H5FD_SUBFILING_IOC_SELECTION_CRITERIA" +/** + * \def H5FD_SUBFILING_SUBFILE_PREFIX + * Macro for name of the environment variable that specifies a prefix + * to apply to the filenames generated for subfiles + * + * The value set for this environment variable is interpreted as a + * pathname. + */ +#define H5FD_SUBFILING_SUBFILE_PREFIX "H5FD_SUBFILING_SUBFILE_PREFIX" + +/** + * \enum H5FD_subfiling_ioc_select_t + * This enum defines the various constants to allow different + * allocations of MPI ranks as I/O concentrators. + * + * \var SELECT_IOC_ONE_PER_NODE + * Default selection method. One MPI rank per node is used as an + * I/O concentrator. If this selection method is used, the number + * of I/O concentrators per node can be adjusted with the + * #H5FD_SUBFILING_IOC_PER_NODE environment variable. + * + * \var SELECT_IOC_EVERY_NTH_RANK + * Starting with MPI rank 0, a stride of 'N' is applied to the MPI + * rank values to determine the next I/O concentrator. The + * #H5FD_SUBFILING_IOC_SELECTION_CRITERIA environment variable must + * be set to the value desired for 'N'. + * + * \var SELECT_IOC_WITH_CONFIG + * Currently unsupported. Use a configuration file to determine + * the mapping from MPI ranks to I/O concentrators. The + * #H5FD_SUBFILING_IOC_SELECTION_CRITERIA environment variable must + * be set to the path to the configuration file. + * + * \var SELECT_IOC_TOTAL + * Specifies that a total of 'N' I/O concentrators should be used. + * Starting with MPI rank 0, a stride of 'MPI comm size' / 'N' is + * applied to the MPI rank values to determine the next I/O + * concentrator. The #H5FD_SUBFILING_IOC_SELECTION_CRITERIA + * environment variable must be set to the value desired for 'N'. + * + * \var ioc_selection_options + * Unused. Sentinel value + */ +typedef enum { + SELECT_IOC_ONE_PER_NODE = 0, /* Default */ + SELECT_IOC_EVERY_NTH_RANK, /* Starting at rank 0, select-next += N */ + SELECT_IOC_WITH_CONFIG, /* NOT IMPLEMENTED: Read-from-file */ + SELECT_IOC_TOTAL, /* Starting at rank 0, mpi_size / total */ + ioc_selection_options /* Sentinel value */ + /* NOTE: Add to the Fortran constants (H5f90global.F90) when adding new entries */ +} H5FD_subfiling_ioc_select_t; + +/** + * \struct H5FD_subfiling_params_t + * \brief Subfiling parameter structure that is shared between the #H5FD_SUBFILING + * and #H5FD_IOC drivers + * + * \var H5FD_subfiling_ioc_select_t H5FD_subfiling_params_t::ioc_selection + * The method to use for selecting MPI ranks to be I/O concentrators. The + * current default is to select one MPI rank per node to be an I/O concentrator. + * Refer to #H5FD_subfiling_ioc_select_t for a description of the algorithms + * available for use. + * + * \var int64_t H5FD_subfiling_params_t::stripe_size + * The stripe size defines the size (in bytes) of the data stripes in the + * subfiles for the logical HDF5 file. Data is striped across the subfiles + * in a round-robin wrap-around fashion in segments equal to the stripe size. + * + * For example, in an HDF5 file consisting of four subfiles with a 1MiB stripe + * size, the first and fifth 1MiB of data would reside in the first subfile, + * the second and sixth 1MiB of data would reside in the second subfile and so + * on. + * + * This value can also be set or adjusted with the #H5FD_SUBFILING_STRIPE_SIZE + * environment variable. + * + * \var int32_t H5FD_subfiling_params_t::stripe_count + * The target number of subfiles to use for the logical HDF5 file. The current + * default is to use one subfile per node, but it can be useful to set a + * different target number of subfiles, especially if the HDF5 application will + * pre-create the HDF5 file on a single MPI rank. In that particular case, the + * single rank will need to know how many subfiles the logical HDF5 file will + * consist of in order to properly pre-create the file. + * + * This value is used in conjunction with the IOC selection method to determine + * which MPI ranks will be assigned as I/O concentrators. Alternatively, the + * mapping between MPI ranks and I/O concentrators can be set or adjusted with a + * combination of the #ioc_selection field and the #H5FD_SUBFILING_IOC_PER_NODE + * and #H5FD_SUBFILING_IOC_SELECTION_CRITERIA environment variables. + */ +typedef struct H5FD_subfiling_params_t { + H5FD_subfiling_ioc_select_t ioc_selection; /* Method to select I/O concentrators */ + int64_t stripe_size; /* Size (in bytes) of data stripes in subfiles */ + int32_t stripe_count; /* Target number of subfiles to use */ +} H5FD_subfiling_params_t; + +//! <!-- [H5FD_subfiling_config_t_snip] --> +/** + * \struct H5FD_subfiling_config_t + * \brief Configuration structure for H5Pset_fapl_subfiling() / H5Pget_fapl_subfiling() + * + * \details H5FD_subfiling_config_t is a public structure that is used to pass + * subfiling configuration data to the #H5FD_SUBFILING driver via + * a File Access Property List. A pointer to an instance of this structure + * is a parameter to H5Pset_fapl_subfiling() and H5Pget_fapl_subfiling(). + * + * \var uint32_t H5FD_subfiling_config_t::magic + * A somewhat unique number which distinguishes the #H5FD_SUBFILING driver + * from other drivers. Used in combination with a version number, it can + * help to validate a user-generated File Access Property List. This field + * should be set to #H5FD_SUBFILING_FAPL_MAGIC. + * + * \var uint32_t H5FD_subfiling_config_t::version + * Version number of the H5FD_subfiling_config_t structure. Any instance + * passed to H5Pset_fapl_subfiling() / H5Pget_fapl_subfiling() must have + * a recognized version number or an error will be raised. Currently, this + * field should be set to #H5FD_SUBFILING_CURR_FAPL_VERSION. + * + * \var hid_t H5FD_subfiling_config_t::ioc_fapl_id + * The File Access Property List which is setup with the file driver that + * the #H5FD_SUBFILING driver will use for servicing I/O requests to the + * subfiles. Currently, the File Access Property List must be setup with + * the #H5FD_IOC driver by calling H5Pset_fapl_ioc(), but future development + * may allow other file drivers to be used. + * + * \var hbool_t H5FD_subfiling_config_t::require_ioc + * A boolean flag which indicates whether the #H5FD_SUBFILING driver should + * use the #H5FD_IOC driver for its I/O operations. This field should currently + * always be set to TRUE. + * + * \var H5FD_subfiling_params_t H5FD_subfiling_config_t::shared_cfg + * A structure which contains the subfiling parameters that are shared between + * the #H5FD_SUBFILING and #H5FD_IOC drivers. This includes the subfile stripe + * size, stripe count, IOC selection method, etc. + * + */ +typedef struct H5FD_subfiling_config_t { + uint32_t magic; /* Must be set to H5FD_SUBFILING_FAPL_MAGIC */ + uint32_t version; /* Must be set to H5FD_SUBFILING_CURR_FAPL_VERSION */ + hid_t ioc_fapl_id; /* The FAPL setup with the stacked VFD to use for I/O concentrators */ + hbool_t require_ioc; /* Whether to use the IOC VFD (currently must always be TRUE) */ + H5FD_subfiling_params_t shared_cfg; /* Subfiling/IOC parameters (stripe size, stripe count, etc.) */ +} H5FD_subfiling_config_t; +//! <!-- [H5FD_subfiling_config_t_snip] --> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \brief Internal routine to initialize #H5FD_SUBFILING driver. Not meant to be + * called directly by an HDF5 application + */ +H5_DLL hid_t H5FD_subfiling_init(void); +/** + * \ingroup FAPL + * + * \brief Modifies the specified File Access Property List to use the #H5FD_SUBFILING driver + * + * \fapl_id + * \param[in] vfd_config Pointer to #H5FD_SUBFILING driver configuration structure. May be NULL. + * \returns \herr_t + * + * \details H5Pset_fapl_subfiling() modifies the File Access Property List to use the + * #H5FD_SUBFILING driver. + * + * The #H5FD_SUBFILING driver is an MPI-based file driver that allows an + * HDF5 application to distribute a logical HDF5 file across a collection + * of "subfiles" in equal-sized data segment "stripes". I/O to the logical + * HDF5 file is then directed to the appropriate "subfile" according to the + * #H5FD_SUBFILING configuration and a system of I/O concentrators, which + * are MPI ranks operating worker threads. + * + * By allowing a configurable stripe size, number of I/O concentrators and + * method for selecting MPI ranks as I/O concentrators, the #H5FD_SUBFILING + * driver aims to enable an HDF5 application to find a middle ground between + * the single shared file and file-per-process approaches to parallel file I/O + * for the particular machine the application is running on. In general, the + * goal is to avoid some of the complexity of the file-per-process approach + * while also minimizing the locking issues of the single shared file approach + * on a parallel file system. + * + * \note Since the #H5FD_SUBFILING driver is an MPI-based file driver, the HDF5 + * application should ensure that H5Pset_mpi_params() is called before this + * routine so that the appropriate MPI communicator and info objects will be + * setup for use by the #H5FD_SUBFILING and #H5FD_IOC drivers. + * + * \note The current architecture of the #H5FD_SUBFILING driver requires that the + * HDF5 application must have been initialized with MPI_Init_thread() using + * a value of MPI_THREAD_MULTIPLE for the thread support level. + * + * \note The \p vfd_config parameter may be NULL. In this case, the reference + * implementation I/O concentrator VFD will be used with the default settings + * of one I/O concentrator per node and a stripe size of 32MiB. Refer to the + * H5FD_subfiling_config_t documentation for information about configuration + * for the #H5FD_SUBFILING driver. + * + * \since 1.14.0 + * + */ +H5_DLL herr_t H5Pset_fapl_subfiling(hid_t fapl_id, const H5FD_subfiling_config_t *vfd_config); +/** + * \ingroup FAPL + * + * \brief Queries a File Access Property List for #H5FD_SUBFILING file driver properties + * + * \fapl_id + * \param[out] config_out Pointer to H5FD_subfiling_config_t structure through which the + * #H5FD_SUBFILING file driver properties will be returned. + * + * \returns \herr_t + * + * \details H5Pget_fapl_subfiling() queries the specified File Access Property List for + * #H5FD_SUBFILING driver properties as set by H5Pset_fapl_subfiling(). If the + * #H5FD_SUBFILING driver has not been set on the File Access Property List, a + * default configuration is returned. An HDF5 application may use this + * functionality to manually configure the #H5FD_SUBFILING driver by calling + * H5Pget_fapl_subfiling() on a newly-created File Access Property List, adjusting + * the default values and then calling H5Pset_fapl_subfiling() with the configured + * H5FD_subfiling_config_t structure. + * + * \note H5Pget_fapl_subfiling() returns the #H5FD_SUBFILING driver properties as they + * were initially set for the File Access Property List using H5Pset_fapl_subfiling(). + * Alternatively, the driver properties can be modified at runtime according to values + * set for the #H5FD_SUBFILING_STRIPE_SIZE, #H5FD_SUBFILING_IOC_PER_NODE and + * #H5FD_SUBFILING_IOC_SELECTION_CRITERIA environment variables. However, driver + * properties set through environment variables will not be reflected in what is + * returned by H5Pget_fapl_subfiling(), so an application may need to check those + * environment variables to get accurate values for the #H5FD_SUBFILING driver + * properties. + * + * \since 1.14.0 + * + */ +H5_DLL herr_t H5Pget_fapl_subfiling(hid_t fapl_id, H5FD_subfiling_config_t *config_out); + +#ifdef __cplusplus +} +#endif + +#endif /* H5_HAVE_SUBFILING_VFD */ + +#endif /* H5FDsubfiling_H */ |