Database Model

Synaps stores AlarmHistory, Metrics, MetricAlarm and StatArchive in the Cassandra database.

Following is Cassandra Database model for Synaps. The model can be set up by synaps-syncdb command.

Keyspace Description

The concept of keyspace is a namespace for ColumnFamilies, typically one per application.

The keyspace and replication factor are configurable.

create keyspace synaps
  with placement_strategy = 'SimpleStrategy'
  and strategy_options = {replication_factor : 2}
  and durable_writes = true;

ColumnFamily Description

ColumnFamilies contain multiple columns, each of which has a name, value, and a timestamp, and which are referenced by row keys. SuperColumns can be thought of as columns that themselves have subcolumns.

Synaps has three ColumnFamilies(AlarmHistory, Metric and MetricAlarm) and one SuperColumnFamily(StatArchive).

AlarmHistory

When an alarm or its status is created or updated, alarm history data will be added as a row.

create column family AlarmHistory
  with column_type = 'Standard'
  and comparator = 'AsciiType'
  and default_validation_class = 'BytesType'
  and key_validation_class = 'LexicalUUIDType'
  and read_repair_chance = 1.0
  and dclocal_read_repair_chance = 0.0
  and gc_grace = 864000
  and min_compaction_threshold = 4
  and max_compaction_threshold = 32
  and replicate_on_write = true
  and compaction_strategy = 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'
  and caching = 'KEYS_ONLY'
  and column_metadata = [
    {column_name : 'history_summary',
    validation_class : UTF8Type},
    {column_name : 'alarm_name',
    validation_class : UTF8Type,
    index_name : 'AlarmHistory_alarm_name_idx',
    index_type : 0},
    {column_name : 'timestamp',
    validation_class : DateType,
    index_name : 'AlarmHistory_timestamp_idx',
    index_type : 0},
    {column_name : 'history_data',
    validation_class : UTF8Type},
    {column_name : 'history_item_type',
    validation_class : UTF8Type,
    index_name : 'AlarmHistory_history_item_type_idx',
    index_type : 0},
    {column_name : 'alarm_key',
    validation_class : LexicalUUIDType,
    index_name : 'AlarmHistory_alarm_key_idx',
    index_type : 0},
    {column_name : 'project_id',
    validation_class : UTF8Type,
    index_name : 'AlarmHistory_project_id_idx',
    index_type : 0}]
  and compression_options = {'sstable_compression' : 'org.apache.cassandra.io.compress.SnappyCompressor'};

Metric

This column failmiy represents Metric.

create column family Metric
  with column_type = 'Standard'
  and comparator = 'AsciiType'
  and default_validation_class = 'BytesType'
  and key_validation_class = 'LexicalUUIDType'
  and read_repair_chance = 1.0
  and dclocal_read_repair_chance = 0.0
  and gc_grace = 864000
  and min_compaction_threshold = 4
  and max_compaction_threshold = 32
  and replicate_on_write = true
  and compaction_strategy = 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'
  and caching = 'KEYS_ONLY'
  and column_metadata = [
    {column_name : 'updated_timestamp',
    validation_class : DateType,
    index_name : 'Metric_updated_timestamp_idx',
    index_type : 0},
    {column_name : 'unit',
    validation_class : UTF8Type},
    {column_name : 'namespace',
    validation_class : UTF8Type,
    index_name : 'Metric_namespace_idx',
    index_type : 0},
    {column_name : 'dimensions',
    validation_class : UTF8Type,
    index_name : 'Metric_dimensions_idx',
    index_type : 0},
    {column_name : 'created_timestamp',
    validation_class : DateType,
    index_name : 'Metric_created_timestamp_idx',
    index_type : 0},
    {column_name : 'name',
    validation_class : UTF8Type,
    index_name : 'Metric_name_idx',
    index_type : 0},
    {column_name : 'project_id',
    validation_class : UTF8Type,
    index_name : 'Metric_project_id_idx',
    index_type : 0}]
  and compression_options = {'sstable_compression' : 'org.apache.cassandra.io.compress.SnappyCompressor'};

MetricAlarm

This column failmiy represents Metric.

create column family MetricAlarm
  with column_type = 'Standard'
  and comparator = 'AsciiType'
  and default_validation_class = 'BytesType'
  and key_validation_class = 'LexicalUUIDType'
  and read_repair_chance = 1.0
  and dclocal_read_repair_chance = 0.0
  and gc_grace = 864000
  and min_compaction_threshold = 4
  and max_compaction_threshold = 32
  and replicate_on_write = true
  and compaction_strategy = 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'
  and caching = 'KEYS_ONLY'
  and column_metadata = [
    {column_name : 'unit',
    validation_class : UTF8Type},
    {column_name : 'state_updated_timestamp',
    validation_class : DateType,
    index_name : 'MetricAlarm_state_updated_timestamp_idx',
    index_type : 0},
    {column_name : 'threshold',
    validation_class : DoubleType},
    {column_name : 'period',
    validation_class : IntegerType,
    index_name : 'MetricAlarm_period_idx',
    index_type : 0},
    {column_name : 'comparison_operator',
    validation_class : UTF8Type},
    {column_name : 'dimensions',
    validation_class : UTF8Type},
    {column_name : 'evaluation_periods',
    validation_class : IntegerType},
    {column_name : 'alarm_actions',
    validation_class : UTF8Type},
    {column_name : 'alarm_arn',
    validation_class : UTF8Type},
    {column_name : 'alarm_configuration_updated_timestamp',
    validation_class : DateType,
    index_name : 'MetricAlarm_alarm_configuration_updated_timestamp_idx',
    index_type : 0},
    {column_name : 'state_reason_data',
    validation_class : UTF8Type},
    {column_name : 'alarm_description',
    validation_class : UTF8Type},
    {column_name : 'statistic',
    validation_class : UTF8Type,
    index_name : 'MetricAlarm_statistic_idx',
    index_type : 0},
    {column_name : 'state_value',
    validation_class : UTF8Type,
    index_name : 'MetricAlarm_state_value_idx',
    index_type : 0},
    {column_name : 'alarm_name',
    validation_class : UTF8Type,
    index_name : 'MetricAlarm_alarm_name_idx',
    index_type : 0},
    {column_name : 'namespace',
    validation_class : UTF8Type},
    {column_name : 'state_reason',
    validation_class : UTF8Type},
    {column_name : 'metric_key',
    validation_class : LexicalUUIDType,
    index_name : 'MetricAlarm_metric_key_idx',
    index_type : 0},
    {column_name : 'insufficient_data_actions',
    validation_class : UTF8Type},
    {column_name : 'metric_name',
    validation_class : UTF8Type},
    {column_name : 'actions_enabled',
    validation_class : BooleanType},
    {column_name : 'project_id',
    validation_class : UTF8Type,
    index_name : 'MetricAlarm_project_id_idx',
    index_type : 0},
    {column_name : 'ok_actions',
    validation_class : UTF8Type}]
  and compression_options = {'sstable_compression' : 'org.apache.cassandra.io.compress.SnappyCompressor'};

StatArchive

This super column failmiy is for storing metric statistics. It holds time-series data aggregated per minute. Its super column key is AVERAGE, MAXIMUM, MINIMUM, SAMPLECOUNT and SUM.

create column family StatArchive
  with column_type = 'Super'
  and comparator = 'AsciiType'
  and subcomparator = 'DateType'
  and default_validation_class = 'DoubleType'
  and key_validation_class = 'LexicalUUIDType'
  and read_repair_chance = 1.0
  and dclocal_read_repair_chance = 0.0
  and gc_grace = 864000
  and min_compaction_threshold = 4
  and max_compaction_threshold = 32
  and replicate_on_write = true
  and compaction_strategy = 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'
  and caching = 'KEYS_ONLY'
  and compression_options = {'sstable_compression' : 'org.apache.cassandra.io.compress.SnappyCompressor'};