Appendix A: Statistics

This topic describes statistics used to monitor system operation. The Core services provide a very large number of statistics for monitoring the operation of the system. Some of them are useful for monitoring performance, while some of them exist for monitoring the operation of the system or for debugging purposes.

Statistics in /database/stats

The following table shows the meaning of the statistics in /database/stats .

Statistic Meaning
meta.bytes , packet.bytes , session.bytes The total size of data (in bytes) stored in each database
meta.first.id , packet.first.id , session.first.id The first meta ID, packet ID, and session ID, respectively, stored in the database
meta.last.id , packet.last.id , session.last.id The last meta ID, packet ID, and session ID, respectively, stored in the database
meta.oldest.file.time , packet.oldest.file.time , session.oldest.file.time The creation date of the oldest file in each database
meta.rate , packet.rate , session.rate The count of the number of meta, packet, and session objects added to each database over the last second
meta.total , packet.total , session.total The total number of meta, packet, and session objects within each database
meta.volume.bytes , packet.volume.bytes , session.volume.bytes The approximate total volume size (in bytes) for all directories used by each database
meta.free.space , packet.free.space , session.free.space The approximate total unused space (in bytes) across all directories used by each database

Statistics in /index/stats

The following table shows the meaning of the statistics in /index/stats .

Statistic Meaning
checkpoint.page , checkpoint.summary The last objects stored the last time an index save was created (debugging)
index.bytes An approximate measure of how much disk space is required by index files
index.last.load.time The timestamp when the current index configuration was loaded from the index configuration files
memory.used An approximate measure of how much memory is occupied by the index
page.first.id , summary.first.id The first page and summary object stored in the index (debugging)
page.last.id , summary.last.id The last page and summary object stored in the index (debugging)
page.total , summary.total Number of pages and summaries in the index (debugging)
session.first.id The ID of the first session indexed
session.last.id The ID of the last session indexed
sessions.since.save The number of sessions currently held by the current index slice
values.added The number of unique values added to the current index slice
slices.total The number of slices in the index
time.begin The oldest time meta indexed
time.end The most recent time meta indexed
updater.state The status of background reindexer

Statistics in /sdk/stats

The following table shows the meaning of the statistics in /sdk/stats

Statistic Meaning
cache.window.time.begin The beginning of the current time enforced by cache.window.minutes
cache.window.time.end The end of the current time enforced by cache.window.minutes
queries.active The number of queries currently executing in the index
queries.queued The number of queries waiting for execution
values.calls The number of calls made to the "values" function since the process was started
values.calls.cached The number of calls made to the "values" function that were resolved by the values call result cache

Per-query Statistics

SDK operations, such as query and values, provide information about their execution status in /sdk/config/stats/queries/<handleid> , where <handleid> is a unique identifier for the query operation.

The following table shows the meaning of per-query statistics.

Statistic Meaning
channel.path This stat provides a link to the connection channel over which the operation is communicating. This channel is used to communicate results back to the client.
query.type The type of operation being performed, such as queries or values
query The complete set of parameters given to the query
query.progress The percentage of the query execution that has completed
query.status A message describing what stage of the query execution is currently occurring
running.since The time at which the query began execution
user The user name that executed the query