Event Lines

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The TimeLine diagram has several event lines showing you important events that occur during tracing of your application. The events correspond to persistent data handling and help you judge the workload of the ObjectStore client.

The following diagram shows you an example of the event lines. Note that the Client Counters/Ratios diagram is not shown in this example.

The event lines are only shown if the corresponding events are selected. Generic events, and trace and transaction events are selected by default. You can select events in the Select Events dialog of the Options menu.

Depending on the zoom level, overlapping events indicated by arrowheads can imply an incorrect time sequence. To see the correct time sequence, zoom in on this part of the diagram interval so that the events no longer overlap each other.

Each line represents a different event category as discussed in the next sections.

Generic Events Line

This line shows you the events raised by your application. You can assign a different color to each generic event type. Generic events are indicated by the following symbols:

Single-event (generated with raise_single method)
Before-event (generated with raise_before method)
After-event (generated with raise_after method)

Trace and Transaction Events Line

This line shows you transaction begin, retry, commit, and abort events. It also shows you trace start and stop, suspend and resume events. These event types are indicated by colored arrowheads. A thin line represents the outermost transaction that is active at the time displayed on the time axis. A thick line represents the period of committing a transaction. An empty bar represents the period of aborting a transaction.

Transaction begin
Transaction retry
Transaction commit
Transaction abort
Trace start
Trace stop
Trace suspend
Trace resume

Miscellaneous Events Line

This line shows you different types of events that are indicated by colored squares or arrowheads:

Client environment change events

Errors during persistent data handling:
Timeout
Deadlock
Exception

Errors

Database before-open
Database after-open
Database before-close
Database after-close

Database events

Note: For database after-open and database before-close only, the name of the database is shown in the status line and in the Database Event Details dialog

.

Collection events (start and stop):
Add index by os_collection::add_index()
Drop index by os _collection::drop_index()
Parse index by os_index_path::create()
Parse query by os_coll_query::create()
Execute query: os_collection::query()os_collection::query_pick()os_collection::query_exists()
Change representation: os_collection::change_rep()

Collection events

Time intervals for page handling events that OPE cannot relate to an individual page
Return memory processing started
Return memory processing ended
Acquire lock processing started
Acquire lock processing ended

Time intervals

Note that an ad hoc query

os_collection::query | query_pick | query_exists( <type>, <expr>)

results in consecutive events, one event for the parsing of the expression and one event for the execution of the query.

When your mouse pointer is on an event indicating an error or an event ending with an error, OPE shows you the reason for the error in the status line. The event details dialog also gives you this information. Depending on the event type, the reason for an error can be deadlock, timeout, or other error.