Merging upstream version 1.11.0+dfsg.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 886 insertions, 0 deletions

diff --git a/database/rrd.h b/database/rrd.h
new file mode 100644
index 00000000..19eb100c
--- /dev/null
+++ b/database/rrd.h
@@ -0,0 +1,886 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_RRD_H
+#define NETDATA_RRD_H 1
+
+// forward typedefs
+typedef struct rrdhost RRDHOST;
+typedef struct rrddim RRDDIM;
+typedef struct rrdset RRDSET;
+typedef struct rrdvar RRDVAR;
+typedef struct rrdsetvar RRDSETVAR;
+typedef struct rrddimvar RRDDIMVAR;
+typedef struct rrdcalc RRDCALC;
+typedef struct rrdcalctemplate RRDCALCTEMPLATE;
+typedef struct alarm_entry ALARM_ENTRY;
+
+#include "../daemon/common.h"
+#include "web/api/queries/query.h"
+#include "rrdvar.h"
+#include "rrdsetvar.h"
+#include "rrddimvar.h"
+#include "rrdcalc.h"
+#include "rrdcalctemplate.h"
+
+#define UPDATE_EVERY 1
+#define UPDATE_EVERY_MAX 3600
+
+#define RRD_DEFAULT_HISTORY_ENTRIES 3600
+#define RRD_HISTORY_ENTRIES_MAX (86400*365)
+
+extern int default_rrd_update_every;
+extern int default_rrd_history_entries;
+extern int gap_when_lost_iterations_above;
+
+#define RRD_ID_LENGTH_MAX 200
+
+#define RRDSET_MAGIC        "NETDATA RRD SET FILE V019"
+#define RRDDIMENSION_MAGIC  "NETDATA RRD DIMENSION FILE V019"
+
+typedef long long total_number;
+#define TOTAL_NUMBER_FORMAT "%lld"
+
+// ----------------------------------------------------------------------------
+// chart types
+
+typedef enum rrdset_type {
+    RRDSET_TYPE_LINE    = 0,
+    RRDSET_TYPE_AREA    = 1,
+    RRDSET_TYPE_STACKED = 2
+} RRDSET_TYPE;
+
+#define RRDSET_TYPE_LINE_NAME "line"
+#define RRDSET_TYPE_AREA_NAME "area"
+#define RRDSET_TYPE_STACKED_NAME "stacked"
+
+RRDSET_TYPE rrdset_type_id(const char *name);
+const char *rrdset_type_name(RRDSET_TYPE chart_type);
+
+
+// ----------------------------------------------------------------------------
+// memory mode
+
+typedef enum rrd_memory_mode {
+    RRD_MEMORY_MODE_NONE = 0,
+    RRD_MEMORY_MODE_RAM  = 1,
+    RRD_MEMORY_MODE_MAP  = 2,
+    RRD_MEMORY_MODE_SAVE = 3,
+    RRD_MEMORY_MODE_ALLOC = 4
+} RRD_MEMORY_MODE;
+
+#define RRD_MEMORY_MODE_NONE_NAME "none"
+#define RRD_MEMORY_MODE_RAM_NAME "ram"
+#define RRD_MEMORY_MODE_MAP_NAME "map"
+#define RRD_MEMORY_MODE_SAVE_NAME "save"
+#define RRD_MEMORY_MODE_ALLOC_NAME "alloc"
+
+extern RRD_MEMORY_MODE default_rrd_memory_mode;
+
+extern const char *rrd_memory_mode_name(RRD_MEMORY_MODE id);
+extern RRD_MEMORY_MODE rrd_memory_mode_id(const char *name);
+
+
+// ----------------------------------------------------------------------------
+// algorithms types
+
+typedef enum rrd_algorithm {
+    RRD_ALGORITHM_ABSOLUTE              = 0,
+    RRD_ALGORITHM_INCREMENTAL           = 1,
+    RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL = 2,
+    RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL  = 3
+} RRD_ALGORITHM;
+
+#define RRD_ALGORITHM_ABSOLUTE_NAME                "absolute"
+#define RRD_ALGORITHM_INCREMENTAL_NAME             "incremental"
+#define RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL_NAME   "percentage-of-incremental-row"
+#define RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL_NAME    "percentage-of-absolute-row"
+
+extern RRD_ALGORITHM rrd_algorithm_id(const char *name);
+extern const char *rrd_algorithm_name(RRD_ALGORITHM algorithm);
+
+// ----------------------------------------------------------------------------
+// RRD FAMILY
+
+struct rrdfamily {
+    avl avl;
+
+    const char *family;
+    uint32_t hash_family;
+
+    size_t use_count;
+
+    avl_tree_lock rrdvar_root_index;
+};
+typedef struct rrdfamily RRDFAMILY;
+
+
+// ----------------------------------------------------------------------------
+// flags
+// use this for configuration flags, not for state control
+// flags are set/unset in a manner that is not thread safe
+// and may lead to missing information.
+
+typedef enum rrddim_flags {
+    RRDDIM_FLAG_NONE                            = 0,
+    RRDDIM_FLAG_HIDDEN                          = (1 << 0),  // this dimension will not be offered to callers
+    RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS = (1 << 1)   // do not offer RESET or OVERFLOW info to callers
+} RRDDIM_FLAGS;
+
+#ifdef HAVE_C___ATOMIC
+#define rrddim_flag_check(rd, flag) (__atomic_load_n(&((rd)->flags), __ATOMIC_SEQ_CST) & (flag))
+#define rrddim_flag_set(rd, flag)   __atomic_or_fetch(&((rd)->flags), (flag), __ATOMIC_SEQ_CST)
+#define rrddim_flag_clear(rd, flag) __atomic_and_fetch(&((rd)->flags), ~(flag), __ATOMIC_SEQ_CST)
+#else
+#define rrddim_flag_check(rd, flag) ((rd)->flags & (flag))
+#define rrddim_flag_set(rd, flag)   (rd)->flags |= (flag)
+#define rrddim_flag_clear(rd, flag) (rd)->flags &= ~(flag)
+#endif
+
+
+// ----------------------------------------------------------------------------
+// RRD DIMENSION - this is a metric
+
+struct rrddim {
+    // ------------------------------------------------------------------------
+    // binary indexing structures
+
+    avl avl;                                        // the binary index - this has to be first member!
+
+    // ------------------------------------------------------------------------
+    // the dimension definition
+
+    const char *id;                                 // the id of this dimension (for internal identification)
+    const char *name;                               // the name of this dimension (as presented to user)
+                                                    // this is a pointer to the config structure
+                                                    // since the config always has a higher priority
+                                                    // (the user overwrites the name of the charts)
+                                                    // DO NOT FREE THIS - IT IS ALLOCATED IN CONFIG
+
+    RRD_ALGORITHM algorithm;                        // the algorithm that is applied to add new collected values
+    RRD_MEMORY_MODE rrd_memory_mode;                // the memory mode for this dimension
+
+    collected_number multiplier;                    // the multiplier of the collected values
+    collected_number divisor;                       // the divider of the collected values
+
+    uint32_t flags;                                 // configuration flags for the dimension
+
+    // ------------------------------------------------------------------------
+    // members for temporary data we need for calculations
+
+    uint32_t hash;                                  // a simple hash of the id, to speed up searching / indexing
+                                                    // instead of strcmp() every item in the binary index
+                                                    // we first compare the hashes
+
+    uint32_t hash_name;                             // a simple hash of the name
+
+    char *cache_filename;                           // the filename we load/save from/to this set
+
+    size_t collections_counter;                     // the number of times we added values to this rrdim
+    size_t unused[10];
+
+    unsigned int updated:1;                         // 1 when the dimension has been updated since the last processing
+    unsigned int exposed:1;                         // 1 when set what have sent this dimension to the central netdata
+
+    struct timeval last_collected_time;             // when was this dimension last updated
+                                                    // this is actual date time we updated the last_collected_value
+                                                    // THIS IS DIFFERENT FROM THE SAME MEMBER OF RRDSET
+
+    calculated_number calculated_value;             // the current calculated value, after applying the algorithm - resets to zero after being used
+    calculated_number last_calculated_value;        // the last calculated value processed
+
+    calculated_number last_stored_value;            // the last value as stored in the database (after interpolation)
+
+    collected_number collected_value;               // the current value, as collected - resets to 0 after being used
+    collected_number last_collected_value;          // the last value that was collected, after being processed
+
+    // the *_volume members are used to calculate the accuracy of the rounding done by the
+    // storage number - they are printed to debug.log when debug is enabled for a set.
+    calculated_number collected_volume;             // the sum of all collected values so far
+    calculated_number stored_volume;                // the sum of all stored values so far
+
+    struct rrddim *next;                            // linking of dimensions within the same data set
+    struct rrdset *rrdset;
+
+    // ------------------------------------------------------------------------
+    // members for checking the data when loading from disk
+
+    long entries;                                   // how many entries this dimension has in ram
+                                                    // this is the same to the entries of the data set
+                                                    // we set it here, to check the data when we load it from disk.
+
+    int update_every;                               // every how many seconds is this updated
+
+    size_t memsize;                                 // the memory allocated for this dimension
+
+    char magic[sizeof(RRDDIMENSION_MAGIC) + 1];     // a string to be saved, used to identify our data file
+
+    struct rrddimvar *variables;
+
+    // ------------------------------------------------------------------------
+    // the values stored in this dimension, using our floating point numbers
+
+    storage_number values[];                        // the array of values - THIS HAS TO BE THE LAST MEMBER
+};
+
+// ----------------------------------------------------------------------------
+// these loop macros make sure the linked list is accessed with the right lock
+
+#define rrddim_foreach_read(rd, st) \
+    for((rd) = (st)->dimensions, rrdset_check_rdlock(st); (rd) ; (rd) = (rd)->next)
+
+#define rrddim_foreach_write(rd, st) \
+    for((rd) = (st)->dimensions, rrdset_check_wrlock(st); (rd) ; (rd) = (rd)->next)
+
+
+// ----------------------------------------------------------------------------
+// RRDSET - this is a chart
+
+// use this for configuration flags, not for state control
+// flags are set/unset in a manner that is not thread safe
+// and may lead to missing information.
+
+typedef enum rrdset_flags {
+    RRDSET_FLAG_ENABLED           = 1 << 0, // enables or disables a chart
+    RRDSET_FLAG_DETAIL            = 1 << 1, // if set, the data set should be considered as a detail of another
+                                         // (the master data set should be the one that has the same family and is not detail)
+    RRDSET_FLAG_DEBUG             = 1 << 2, // enables or disables debugging for a chart
+    RRDSET_FLAG_OBSOLETE          = 1 << 3, // this is marked by the collector/module as obsolete
+    RRDSET_FLAG_BACKEND_SEND      = 1 << 4, // if set, this chart should be sent to backends
+    RRDSET_FLAG_BACKEND_IGNORE    = 1 << 5, // if set, this chart should not be sent to backends
+    RRDSET_FLAG_UPSTREAM_SEND     = 1 << 6, // if set, this chart should be sent upstream (streaming)
+    RRDSET_FLAG_UPSTREAM_IGNORE   = 1 << 7, // if set, this chart should not be sent upstream (streaming)
+    RRDSET_FLAG_UPSTREAM_EXPOSED  = 1 << 8, // if set, we have sent this chart definition to netdata master (streaming)
+    RRDSET_FLAG_STORE_FIRST       = 1 << 9, // if set, do not eliminate the first collection during interpolation
+    RRDSET_FLAG_HETEROGENEOUS     = 1 << 10, // if set, the chart is not homogeneous (dimensions in it have multiple algorithms, multipliers or dividers)
+    RRDSET_FLAG_HOMEGENEOUS_CHECK = 1 << 11, // if set, the chart should be checked to determine if the dimensions as homogeneous
+    RRDSET_FLAG_HIDDEN            = 1 << 12, // if set, do not show this chart on the dashboard, but use it for backends
+    RRDSET_FLAG_SYNC_CLOCK        = 1 << 13, // if set, microseconds on next data collection will be ignored (the chart will be synced to now)
+} RRDSET_FLAGS;
+
+#ifdef HAVE_C___ATOMIC
+#define rrdset_flag_check(st, flag) (__atomic_load_n(&((st)->flags), __ATOMIC_SEQ_CST) & (flag))
+#define rrdset_flag_set(st, flag)   __atomic_or_fetch(&((st)->flags), flag, __ATOMIC_SEQ_CST)
+#define rrdset_flag_clear(st, flag) __atomic_and_fetch(&((st)->flags), ~flag, __ATOMIC_SEQ_CST)
+#else
+#define rrdset_flag_check(st, flag) ((st)->flags & (flag))
+#define rrdset_flag_set(st, flag)   (st)->flags |= (flag)
+#define rrdset_flag_clear(st, flag) (st)->flags &= ~(flag)
+#endif
+#define rrdset_flag_check_noatomic(st, flag) ((st)->flags & (flag))
+
+struct rrdset {
+    // ------------------------------------------------------------------------
+    // binary indexing structures
+
+    avl avl;                                        // the index, with key the id - this has to be first!
+    avl avlname;                                    // the index, with key the name
+
+    // ------------------------------------------------------------------------
+    // the set configuration
+
+    char id[RRD_ID_LENGTH_MAX + 1];                 // id of the data set
+
+    const char *name;                               // the name of this dimension (as presented to user)
+                                                    // this is a pointer to the config structure
+                                                    // since the config always has a higher priority
+                                                    // (the user overwrites the name of the charts)
+
+    char *config_section;                           // the config section for the chart
+
+    char *type;                                     // the type of graph RRD_TYPE_* (a category, for determining graphing options)
+    char *family;                                   // grouping sets under the same family
+    char *title;                                    // title shown to user
+    char *units;                                    // units of measurement
+
+    char *context;                                  // the template of this data set
+    uint32_t hash_context;                          // the hash of the chart's context
+
+    RRDSET_TYPE chart_type;                         // line, area, stacked
+
+    int update_every;                               // every how many seconds is this updated?
+
+    long entries;                                   // total number of entries in the data set
+
+    long current_entry;                             // the entry that is currently being updated
+                                                    // it goes around in a round-robin fashion
+
+    RRDSET_FLAGS flags;                             // configuration flags
+
+    int gap_when_lost_iterations_above;             // after how many lost iterations a gap should be stored
+                                                    // netdata will interpolate values for gaps lower than this
+
+    long priority;                                  // the sorting priority of this chart
+
+
+    // ------------------------------------------------------------------------
+    // members for temporary data we need for calculations
+
+    RRD_MEMORY_MODE rrd_memory_mode;                // if set to 1, this is memory mapped
+
+    char *cache_dir;                                // the directory to store dimensions
+    char cache_filename[FILENAME_MAX+1];            // the filename to store this set
+
+    netdata_rwlock_t rrdset_rwlock;                 // protects dimensions linked list
+
+    size_t counter;                                 // the number of times we added values to this database
+    size_t counter_done;                            // the number of times rrdset_done() has been called
+
+    time_t last_accessed_time;                      // the last time this RRDSET has been accessed
+    time_t upstream_resync_time;                    // the timestamp up to which we should resync clock upstream
+
+    char *plugin_name;                              // the name of the plugin that generated this
+    char *module_name;                              // the name of the plugin module that generated this
+
+    size_t unused[6];
+
+    uint32_t hash;                                  // a simple hash on the id, to speed up searching
+                                                    // we first compare hashes, and only if the hashes are equal we do string comparisons
+
+    uint32_t hash_name;                             // a simple hash on the name
+
+    usec_t usec_since_last_update;                  // the time in microseconds since the last collection of data
+
+    struct timeval last_updated;                    // when this data set was last updated (updated every time the rrd_stats_done() function)
+    struct timeval last_collected_time;             // when did this data set last collected values
+
+    total_number collected_total;                   // used internally to calculate percentages
+    total_number last_collected_total;              // used internally to calculate percentages
+
+    RRDFAMILY *rrdfamily;                           // pointer to RRDFAMILY this chart belongs to
+    RRDHOST *rrdhost;                               // pointer to RRDHOST this chart belongs to
+
+    struct rrdset *next;                            // linking of rrdsets
+
+    // ------------------------------------------------------------------------
+    // local variables
+
+    calculated_number green;                        // green threshold for this chart
+    calculated_number red;                          // red threshold for this chart
+
+    avl_tree_lock rrdvar_root_index;                // RRDVAR index for this chart
+    RRDSETVAR *variables;                           // RRDSETVAR linked list for this chart (one RRDSETVAR, many RRDVARs)
+    RRDCALC *alarms;                                // RRDCALC linked list for this chart
+
+    // ------------------------------------------------------------------------
+    // members for checking the data when loading from disk
+
+    unsigned long memsize;                          // how much mem we have allocated for this (without dimensions)
+
+    char magic[sizeof(RRDSET_MAGIC) + 1];           // our magic
+
+    // ------------------------------------------------------------------------
+    // the dimensions
+
+    avl_tree_lock dimensions_index;                 // the root of the dimensions index
+    RRDDIM *dimensions;                             // the actual data for every dimension
+
+};
+
+#define rrdset_rdlock(st) netdata_rwlock_rdlock(&((st)->rrdset_rwlock))
+#define rrdset_wrlock(st) netdata_rwlock_wrlock(&((st)->rrdset_rwlock))
+#define rrdset_unlock(st) netdata_rwlock_unlock(&((st)->rrdset_rwlock))
+
+
+// ----------------------------------------------------------------------------
+// these loop macros make sure the linked list is accessed with the right lock
+
+#define rrdset_foreach_read(st, host) \
+    for((st) = (host)->rrdset_root, rrdhost_check_rdlock(host); st ; (st) = (st)->next)
+
+#define rrdset_foreach_write(st, host) \
+    for((st) = (host)->rrdset_root, rrdhost_check_wrlock(host); st ; (st) = (st)->next)
+
+
+// ----------------------------------------------------------------------------
+// RRDHOST flags
+// use this for configuration flags, not for state control
+// flags are set/unset in a manner that is not thread safe
+// and may lead to missing information.
+
+typedef enum rrdhost_flags {
+    RRDHOST_FLAG_ORPHAN                 = 1 << 0, // this host is orphan (not receiving data)
+    RRDHOST_FLAG_DELETE_OBSOLETE_CHARTS = 1 << 1, // delete files of obsolete charts
+    RRDHOST_FLAG_DELETE_ORPHAN_HOST     = 1 << 2, // delete the entire host when orphan
+    RRDHOST_FLAG_BACKEND_SEND           = 1 << 3, // send it to backends
+    RRDHOST_FLAG_BACKEND_DONT_SEND      = 1 << 4, // don't send it to backends
+} RRDHOST_FLAGS;
+
+#ifdef HAVE_C___ATOMIC
+#define rrdhost_flag_check(host, flag) (__atomic_load_n(&((host)->flags), __ATOMIC_SEQ_CST) & (flag))
+#define rrdhost_flag_set(host, flag)   __atomic_or_fetch(&((host)->flags), flag, __ATOMIC_SEQ_CST)
+#define rrdhost_flag_clear(host, flag) __atomic_and_fetch(&((host)->flags), ~flag, __ATOMIC_SEQ_CST)
+#else
+#define rrdhost_flag_check(host, flag) ((host)->flags & (flag))
+#define rrdhost_flag_set(host, flag)   (host)->flags |= (flag)
+#define rrdhost_flag_clear(host, flag) (host)->flags &= ~(flag)
+#endif
+
+#ifdef NETDATA_INTERNAL_CHECKS
+#define rrdset_debug(st, fmt, args...) do { if(unlikely(debug_flags & D_RRD_STATS && rrdset_flag_check(st, RRDSET_FLAG_DEBUG))) \
+            debug_int(__FILE__, __FUNCTION__, __LINE__, "%s: " fmt, st->name, ##args); } while(0)
+#else
+#define rrdset_debug(st, fmt, args...) debug_dummy()
+#endif
+
+// ----------------------------------------------------------------------------
+// Health data
+
+struct alarm_entry {
+    uint32_t unique_id;
+    uint32_t alarm_id;
+    uint32_t alarm_event_id;
+
+    time_t when;
+    time_t duration;
+    time_t non_clear_duration;
+
+    char *name;
+    uint32_t hash_name;
+
+    char *chart;
+    uint32_t hash_chart;
+
+    char *family;
+
+    char *exec;
+    char *recipient;
+    time_t exec_run_timestamp;
+    int exec_code;
+
+    char *source;
+    char *units;
+    char *info;
+
+    calculated_number old_value;
+    calculated_number new_value;
+
+    char *old_value_string;
+    char *new_value_string;
+
+    RRDCALC_STATUS old_status;
+    RRDCALC_STATUS new_status;
+
+    uint32_t flags;
+
+    int delay;
+    time_t delay_up_to_timestamp;
+
+    uint32_t updated_by_id;
+    uint32_t updates_id;
+
+    struct alarm_entry *next;
+};
+
+
+typedef struct alarm_log {
+    uint32_t next_log_id;
+    uint32_t next_alarm_id;
+    unsigned int count;
+    unsigned int max;
+    ALARM_ENTRY *alarms;
+    netdata_rwlock_t alarm_log_rwlock;
+} ALARM_LOG;
+
+
+// ----------------------------------------------------------------------------
+// RRD HOST
+
+struct rrdhost {
+    avl avl;                                        // the index of hosts
+
+    // ------------------------------------------------------------------------
+    // host information
+
+    char *hostname;                                 // the hostname of this host
+    uint32_t hash_hostname;                         // the hostname hash
+
+    char *registry_hostname;                        // the registry hostname for this host
+
+    char machine_guid[GUID_LEN + 1];                // the unique ID of this host
+    uint32_t hash_machine_guid;                     // the hash of the unique ID
+
+    const char *os;                                 // the O/S type of the host
+    const char *tags;                               // tags for this host
+    const char *timezone;                           // the timezone of the host
+
+    RRDHOST_FLAGS flags;                            // flags about this RRDHOST
+
+    int rrd_update_every;                           // the update frequency of the host
+    long rrd_history_entries;                       // the number of history entries for the host's charts
+    RRD_MEMORY_MODE rrd_memory_mode;                // the memory more for the charts of this host
+
+    char *cache_dir;                                // the directory to save RRD cache files
+    char *varlib_dir;                               // the directory to save health log
+
+    char *program_name;                             // the program name that collects metrics for this host
+    char *program_version;                          // the program version that collects metrics for this host
+
+    // ------------------------------------------------------------------------
+    // streaming of data to remote hosts - rrdpush
+
+    unsigned int rrdpush_send_enabled:1;            // 1 when this host sends metrics to another netdata
+    char *rrdpush_send_destination;                 // where to send metrics to
+    char *rrdpush_send_api_key;                     // the api key at the receiving netdata
+
+    // the following are state information for the threading
+    // streaming metrics from this netdata to an upstream netdata
+    volatile unsigned int rrdpush_sender_spawn:1;   // 1 when the sender thread has been spawn
+    netdata_thread_t rrdpush_sender_thread;         // the sender thread
+
+    volatile unsigned int rrdpush_sender_connected:1; // 1 when the sender is ready to push metrics
+    int rrdpush_sender_socket;                      // the fd of the socket to the remote host, or -1
+
+    volatile unsigned int rrdpush_sender_error_shown:1; // 1 when we have logged a communication error
+    volatile unsigned int rrdpush_sender_join:1;    // 1 when we have to join the sending thread
+
+    SIMPLE_PATTERN *rrdpush_send_charts_matching;   // pattern to match the charts to be sent
+
+    // metrics may be collected asynchronously
+    // these synchronize all the threads willing the write to our sending buffer
+    netdata_mutex_t rrdpush_sender_buffer_mutex;    // exclusive access to rrdpush_sender_buffer
+    int rrdpush_sender_pipe[2];                     // collector to sender thread signaling
+    BUFFER *rrdpush_sender_buffer;                  // collector fills it, sender sends it
+
+
+    // ------------------------------------------------------------------------
+    // streaming of data from remote hosts - rrdpush
+
+    volatile size_t connected_senders;              // when remote hosts are streaming to this
+                                                    // host, this is the counter of connected clients
+
+    time_t senders_disconnected_time;               // the time the last sender was disconnected
+
+    // ------------------------------------------------------------------------
+    // health monitoring options
+
+    unsigned int health_enabled:1;                  // 1 when this host has health enabled
+    time_t health_delay_up_to;                      // a timestamp to delay alarms processing up to
+    char *health_default_exec;                      // the full path of the alarms notifications program
+    char *health_default_recipient;                 // the default recipient for all alarms
+    char *health_log_filename;                      // the alarms event log filename
+    size_t health_log_entries_written;              // the number of alarm events writtern to the alarms event log
+    FILE *health_log_fp;                            // the FILE pointer to the open alarms event log file
+
+    // all RRDCALCs are primarily allocated and linked here
+    // RRDCALCs may be linked to charts at any point
+    // (charts may or may not exist when these are loaded)
+    RRDCALC *alarms;
+
+    ALARM_LOG health_log;                           // alarms historical events (event log)
+    uint32_t health_last_processed_id;              // the last processed health id from the log
+    uint32_t health_max_unique_id;                  // the max alarm log unique id given for the host
+    uint32_t health_max_alarm_id;                   // the max alarm id given for the host
+
+    // templates of alarms
+    // these are used to create alarms when charts
+    // are created or renamed, that match them
+    RRDCALCTEMPLATE *templates;
+
+
+    // ------------------------------------------------------------------------
+    // the charts of the host
+
+    RRDSET *rrdset_root;                            // the host charts
+
+
+    // ------------------------------------------------------------------------
+    // locks
+
+    netdata_rwlock_t rrdhost_rwlock;                // lock for this RRDHOST (protects rrdset_root linked list)
+
+    // ------------------------------------------------------------------------
+    // indexes
+
+    avl_tree_lock rrdset_root_index;                // the host's charts index (by id)
+    avl_tree_lock rrdset_root_index_name;           // the host's charts index (by name)
+
+    avl_tree_lock rrdfamily_root_index;             // the host's chart families index
+    avl_tree_lock rrdvar_root_index;                // the host's chart variables index
+
+    struct rrdhost *next;
+};
+extern RRDHOST *localhost;
+
+#define rrdhost_rdlock(host) netdata_rwlock_rdlock(&((host)->rrdhost_rwlock))
+#define rrdhost_wrlock(host) netdata_rwlock_wrlock(&((host)->rrdhost_rwlock))
+#define rrdhost_unlock(host) netdata_rwlock_unlock(&((host)->rrdhost_rwlock))
+
+// ----------------------------------------------------------------------------
+// these loop macros make sure the linked list is accessed with the right lock
+
+#define rrdhost_foreach_read(var) \
+    for((var) = localhost, rrd_check_rdlock(); var ; (var) = (var)->next)
+
+#define rrdhost_foreach_write(var) \
+    for((var) = localhost, rrd_check_wrlock(); var ; (var) = (var)->next)
+
+
+// ----------------------------------------------------------------------------
+// global lock for all RRDHOSTs
+
+extern netdata_rwlock_t rrd_rwlock;
+
+#define rrd_rdlock() netdata_rwlock_rdlock(&rrd_rwlock)
+#define rrd_wrlock() netdata_rwlock_wrlock(&rrd_rwlock)
+#define rrd_unlock() netdata_rwlock_unlock(&rrd_rwlock)
+
+// ----------------------------------------------------------------------------
+
+extern size_t rrd_hosts_available;
+extern time_t rrdhost_free_orphan_time;
+
+extern void rrd_init(char *hostname);
+
+extern RRDHOST *rrdhost_find_by_hostname(const char *hostname, uint32_t hash);
+extern RRDHOST *rrdhost_find_by_guid(const char *guid, uint32_t hash);
+
+extern RRDHOST *rrdhost_find_or_create(
+        const char *hostname
+        , const char *registry_hostname
+        , const char *guid
+        , const char *os
+        , const char *timezone
+        , const char *tags
+        , const char *program_name
+        , const char *program_version
+        , int update_every
+        , long history
+        , RRD_MEMORY_MODE mode
+        , unsigned int health_enabled
+        , unsigned int rrdpush_enabled
+        , char *rrdpush_destination
+        , char *rrdpush_api_key
+        , char *rrdpush_send_charts_matching
+);
+
+#if defined(NETDATA_INTERNAL_CHECKS) && defined(NETDATA_VERIFY_LOCKS)
+extern void __rrdhost_check_wrlock(RRDHOST *host, const char *file, const char *function, const unsigned long line);
+extern void __rrdhost_check_rdlock(RRDHOST *host, const char *file, const char *function, const unsigned long line);
+extern void __rrdset_check_rdlock(RRDSET *st, const char *file, const char *function, const unsigned long line);
+extern void __rrdset_check_wrlock(RRDSET *st, const char *file, const char *function, const unsigned long line);
+extern void __rrd_check_rdlock(const char *file, const char *function, const unsigned long line);
+extern void __rrd_check_wrlock(const char *file, const char *function, const unsigned long line);
+
+#define rrdhost_check_rdlock(host) __rrdhost_check_rdlock(host, __FILE__, __FUNCTION__, __LINE__)
+#define rrdhost_check_wrlock(host) __rrdhost_check_wrlock(host, __FILE__, __FUNCTION__, __LINE__)
+#define rrdset_check_rdlock(st) __rrdset_check_rdlock(st, __FILE__, __FUNCTION__, __LINE__)
+#define rrdset_check_wrlock(st) __rrdset_check_wrlock(st, __FILE__, __FUNCTION__, __LINE__)
+#define rrd_check_rdlock() __rrd_check_rdlock(__FILE__, __FUNCTION__, __LINE__)
+#define rrd_check_wrlock() __rrd_check_wrlock(__FILE__, __FUNCTION__, __LINE__)
+
+#else
+#define rrdhost_check_rdlock(host) (void)0
+#define rrdhost_check_wrlock(host) (void)0
+#define rrdset_check_rdlock(st) (void)0
+#define rrdset_check_wrlock(st) (void)0
+#define rrd_check_rdlock() (void)0
+#define rrd_check_wrlock() (void)0
+#endif
+
+// ----------------------------------------------------------------------------
+// RRDSET functions
+
+extern int rrdset_set_name(RRDSET *st, const char *name);
+
+extern RRDSET *rrdset_create_custom(RRDHOST *host
+                             , const char *type
+                             , const char *id
+                             , const char *name
+                             , const char *family
+                             , const char *context
+                             , const char *title
+                             , const char *units
+                             , const char *plugin
+                             , const char *module
+                             , long priority
+                             , int update_every
+                             , RRDSET_TYPE chart_type
+                             , RRD_MEMORY_MODE memory_mode
+                             , long history_entries);
+
+#define rrdset_create(host, type, id, name, family, context, title, units, plugin, module, priority, update_every, chart_type) \
+    rrdset_create_custom(host, type, id, name, family, context, title, units, plugin, module, priority, update_every, chart_type, (host)->rrd_memory_mode, (host)->rrd_history_entries)
+
+#define rrdset_create_localhost(type, id, name, family, context, title, units, plugin, module, priority, update_every, chart_type) \
+    rrdset_create(localhost, type, id, name, family, context, title, units, plugin, module, priority, update_every, chart_type)
+
+extern void rrdhost_free_all(void);
+extern void rrdhost_save_all(void);
+extern void rrdhost_cleanup_all(void);
+
+extern void rrdhost_cleanup_orphan_hosts_nolock(RRDHOST *protected);
+extern void rrdhost_free(RRDHOST *host);
+extern void rrdhost_save_charts(RRDHOST *host);
+extern void rrdhost_delete_charts(RRDHOST *host);
+
+extern int rrdhost_should_be_removed(RRDHOST *host, RRDHOST *protected, time_t now);
+
+extern void rrdset_update_heterogeneous_flag(RRDSET *st);
+
+extern RRDSET *rrdset_find(RRDHOST *host, const char *id);
+#define rrdset_find_localhost(id) rrdset_find(localhost, id)
+
+extern RRDSET *rrdset_find_bytype(RRDHOST *host, const char *type, const char *id);
+#define rrdset_find_bytype_localhost(type, id) rrdset_find_bytype(localhost, type, id)
+
+extern RRDSET *rrdset_find_byname(RRDHOST *host, const char *name);
+#define rrdset_find_byname_localhost(name)  rrdset_find_byname(localhost, name)
+
+extern void rrdset_next_usec_unfiltered(RRDSET *st, usec_t microseconds);
+extern void rrdset_next_usec(RRDSET *st, usec_t microseconds);
+#define rrdset_next(st) rrdset_next_usec(st, 0ULL)
+
+extern void rrdset_done(RRDSET *st);
+
+extern void rrdset_is_obsolete(RRDSET *st);
+extern void rrdset_isnot_obsolete(RRDSET *st);
+
+// checks if the RRDSET should be offered to viewers
+#define rrdset_is_available_for_viewers(st) (rrdset_flag_check(st, RRDSET_FLAG_ENABLED) && !rrdset_flag_check(st, RRDSET_FLAG_HIDDEN) && !rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE) && (st)->dimensions && (st)->rrd_memory_mode != RRD_MEMORY_MODE_NONE)
+#define rrdset_is_available_for_backends(st) (rrdset_flag_check(st, RRDSET_FLAG_ENABLED) && !rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE) && (st)->dimensions)
+
+// get the total duration in seconds of the round robin database
+#define rrdset_duration(st) ((time_t)( (((st)->counter >= ((unsigned long)(st)->entries))?(unsigned long)(st)->entries:(st)->counter) * (st)->update_every ))
+
+// get the timestamp of the last entry in the round robin database
+#define rrdset_last_entry_t(st) ((time_t)(((st)->last_updated.tv_sec)))
+
+// get the timestamp of first entry in the round robin database
+#define rrdset_first_entry_t(st) ((time_t)(rrdset_last_entry_t(st) - rrdset_duration(st)))
+
+// get the last slot updated in the round robin database
+#define rrdset_last_slot(st) ((size_t)(((st)->current_entry == 0) ? (st)->entries - 1 : (st)->current_entry - 1))
+
+// get the first / oldest slot updated in the round robin database
+// #define rrdset_first_slot(st) ((size_t)( (((st)->counter >= ((unsigned long)(st)->entries)) ? (unsigned long)( ((unsigned long)(st)->current_entry > 0) ? ((unsigned long)(st)->current_entry) : ((unsigned long)(st)->entries) ) - 1 : 0) ))
+
+// return the slot that has the oldest value
+
+static inline size_t rrdset_first_slot(RRDSET *st) {
+    if(st->counter >= (size_t)st->entries) {
+        // the database has been rotated at least once
+        // the oldest entry is the one that will be next
+        // overwritten by data collection
+        return (size_t)st->current_entry;
+    }
+
+    // we do not have rotated the db yet
+    // so 0 is the first entry
+    return 0;
+}
+
+// get the slot of the round robin database, for the given timestamp (t)
+// it always returns a valid slot, although may not be for the time requested if the time is outside the round robin database
+static inline size_t rrdset_time2slot(RRDSET *st, time_t t) {
+    size_t ret = 0;
+
+    if(t >= rrdset_last_entry_t(st)) {
+        // the requested time is after the last entry we have
+        ret = rrdset_last_slot(st);
+    }
+    else {
+        if(t <= rrdset_first_entry_t(st)) {
+            // the requested time is before the first entry we have
+            ret = rrdset_first_slot(st);
+        }
+        else {
+            if(rrdset_last_slot(st) >= ((rrdset_last_entry_t(st) - t) / (size_t)(st->update_every)))
+                ret = rrdset_last_slot(st) - ((rrdset_last_entry_t(st) - t) / (size_t)(st->update_every));
+            else
+                ret = rrdset_last_slot(st) - ((rrdset_last_entry_t(st) - t) / (size_t)(st->update_every)) + (unsigned long)st->entries;
+        }
+    }
+
+    if(unlikely(ret >= (size_t)st->entries)) {
+        error("INTERNAL ERROR: rrdset_time2slot() on %s returns values outside entries", st->name);
+        ret = (size_t)(st->entries - 1);
+    }
+
+    return ret;
+}
+
+// get the timestamp of a specific slot in the round robin database
+static inline time_t rrdset_slot2time(RRDSET *st, size_t slot) {
+    time_t ret;
+
+    if(slot >= (size_t)st->entries) {
+        error("INTERNAL ERROR: caller of rrdset_slot2time() gives invalid slot %zu", slot);
+        slot = (size_t)st->entries - 1;
+    }
+
+    if(slot > rrdset_last_slot(st)) {
+        ret = rrdset_last_entry_t(st) - (size_t)st->update_every * (rrdset_last_slot(st) - slot + (size_t)st->entries);
+    }
+    else {
+        ret = rrdset_last_entry_t(st) - (size_t)st->update_every;
+    }
+
+    if(unlikely(ret < rrdset_first_entry_t(st))) {
+        error("INTERNAL ERROR: rrdset_slot2time() on %s returns time too far in the past", st->name);
+        ret = rrdset_first_entry_t(st);
+    }
+
+    if(unlikely(ret > rrdset_last_entry_t(st))) {
+        error("INTERNAL ERROR: rrdset_slot2time() on %s returns time into the future", st->name);
+        ret = rrdset_last_entry_t(st);
+    }
+
+    return ret;
+}
+
+// ----------------------------------------------------------------------------
+// RRD DIMENSION functions
+
+extern RRDDIM *rrddim_add_custom(RRDSET *st, const char *id, const char *name, collected_number multiplier, collected_number divisor, RRD_ALGORITHM algorithm, RRD_MEMORY_MODE memory_mode);
+#define rrddim_add(st, id, name, multiplier, divisor, algorithm) rrddim_add_custom(st, id, name, multiplier, divisor, algorithm, (st)->rrd_memory_mode)
+
+extern int rrddim_set_name(RRDSET *st, RRDDIM *rd, const char *name);
+extern int rrddim_set_algorithm(RRDSET *st, RRDDIM *rd, RRD_ALGORITHM algorithm);
+extern int rrddim_set_multiplier(RRDSET *st, RRDDIM *rd, collected_number multiplier);
+extern int rrddim_set_divisor(RRDSET *st, RRDDIM *rd, collected_number divisor);
+
+extern RRDDIM *rrddim_find(RRDSET *st, const char *id);
+
+extern int rrddim_hide(RRDSET *st, const char *id);
+extern int rrddim_unhide(RRDSET *st, const char *id);
+
+extern collected_number rrddim_set_by_pointer(RRDSET *st, RRDDIM *rd, collected_number value);
+extern collected_number rrddim_set(RRDSET *st, const char *id, collected_number value);
+
+extern long align_entries_to_pagesize(RRD_MEMORY_MODE mode, long entries);
+
+// ----------------------------------------------------------------------------
+// RRD internal functions
+
+#ifdef NETDATA_RRD_INTERNALS
+
+extern avl_tree_lock rrdhost_root_index;
+
+extern char *rrdset_strncpyz_name(char *to, const char *from, size_t length);
+extern char *rrdset_cache_dir(RRDHOST *host, const char *id, const char *config_section);
+
+extern void rrddim_free(RRDSET *st, RRDDIM *rd);
+
+extern int rrddim_compare(void* a, void* b);
+extern int rrdset_compare(void* a, void* b);
+extern int rrdset_compare_name(void* a, void* b);
+extern int rrdfamily_compare(void *a, void *b);
+
+extern RRDFAMILY *rrdfamily_create(RRDHOST *host, const char *id);
+extern void rrdfamily_free(RRDHOST *host, RRDFAMILY *rc);
+
+#define rrdset_index_add(host, st) (RRDSET *)avl_insert_lock(&((host)->rrdset_root_index), (avl *)(st))
+#define rrdset_index_del(host, st) (RRDSET *)avl_remove_lock(&((host)->rrdset_root_index), (avl *)(st))
+extern RRDSET *rrdset_index_del_name(RRDHOST *host, RRDSET *st);
+
+extern void rrdset_free(RRDSET *st);
+extern void rrdset_reset(RRDSET *st);
+extern void rrdset_save(RRDSET *st);
+extern void rrdset_delete(RRDSET *st);
+
+extern void rrdhost_cleanup_obsolete_charts(RRDHOST *host);
+
+#endif /* NETDATA_RRD_INTERNALS */
+
+
+#endif /* NETDATA_RRD_H */