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Fix XE ring buffer query timeouts on large buffers #38

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Merged
erikdarlingdata merged 1 commit into from
Feb 15, 2026
Merged

Fix XE ring buffer query timeouts on large buffers #38

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64 changes: 46 additions & 18 deletions Lite/Services/RemoteCollectorService.BlockedProcessReport.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -273,23 +273,37 @@ Use .query() to get XML with structure intact, then CONVERT to nvarchar(max) */
query = $@"
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

DECLARE
@PerformanceMonitor_BlockedProcess TABLE
(
ring_buffer xml NOT NULL
);

INSERT
@PerformanceMonitor_BlockedProcess
(
ring_buffer
)
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_database_session_targets AS xet
JOIN sys.dm_xe_database_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{BlockedProcessXeSessionName}'
AND xet.target_name = N'ring_buffer'
OPTION(RECOMPILE);

SELECT
event_time = evt.value('(@timestamp)[1]', 'datetime2'),
blocked_process_report_xml = CONVERT(nvarchar(max), evt.query('data[@name=""blocked_process""]/value/blocked-process-report'))
FROM
(
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_database_session_targets AS xet
JOIN sys.dm_xe_database_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{BlockedProcessXeSessionName}'
AND xet.target_name = N'ring_buffer'
pmd.ring_buffer
FROM @PerformanceMonitor_BlockedProcess AS pmd
) AS rb
CROSS APPLY rb.ring_xml.nodes('RingBufferTarget/event[@name=""blocked_process_report""]') AS q(evt)
CROSS APPLY rb.ring_buffer.nodes('RingBufferTarget/event[@name=""blocked_process_report""]') AS q(evt)
WHERE evt.value('(@timestamp)[1]', 'datetime2') > DATEADD(MINUTE, -10, SYSUTCDATETIME())
ORDER BY
evt.value('(@timestamp)[1]', 'datetime2') DESC
OPTION(RECOMPILE);";
}
else
Expand All @@ -299,23 +313,37 @@ Use .query() to get XML with structure intact, then CONVERT to nvarchar(max) */
query = $@"
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

DECLARE
@PerformanceMonitor_BlockedProcess TABLE
(
ring_buffer xml NOT NULL
);

INSERT
@PerformanceMonitor_BlockedProcess
(
ring_buffer
)
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_session_targets AS xet
JOIN sys.dm_xe_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{BlockedProcessXeSessionName}'
AND xet.target_name = N'ring_buffer'
OPTION(RECOMPILE);

SELECT
event_time = evt.value('(@timestamp)[1]', 'datetime2'),
blocked_process_report_xml = CONVERT(nvarchar(max), evt.query('data[@name=""blocked_process""]/value/blocked-process-report'))
FROM
(
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_session_targets AS xet
JOIN sys.dm_xe_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{BlockedProcessXeSessionName}'
AND xet.target_name = N'ring_buffer'
pmd.ring_buffer
FROM @PerformanceMonitor_BlockedProcess AS pmd
) AS rb
CROSS APPLY rb.ring_xml.nodes('RingBufferTarget/event[@name=""blocked_process_report""]') AS q(evt)
CROSS APPLY rb.ring_buffer.nodes('RingBufferTarget/event[@name=""blocked_process_report""]') AS q(evt)
WHERE evt.value('(@timestamp)[1]', 'datetime2') > DATEADD(MINUTE, -10, SYSUTCDATETIME())
ORDER BY
evt.value('(@timestamp)[1]', 'datetime2') DESC
OPTION(RECOMPILE);";
}

Expand Down
64 changes: 46 additions & 18 deletions Lite/Services/RemoteCollectorService.Deadlocks.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -271,24 +271,38 @@ Use .query() to get XML with structure intact, then CONVERT to nvarchar(max) */
query = $@"
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

DECLARE
@PerformanceMonitor_Deadlock TABLE
(
ring_buffer xml NOT NULL
);

INSERT
@PerformanceMonitor_Deadlock
(
ring_buffer
)
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_database_session_targets AS xet
JOIN sys.dm_xe_database_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{DeadlockXeSessionName}'
AND xet.target_name = N'ring_buffer'
OPTION(RECOMPILE);

SELECT
deadlock_time = evt.value('(@timestamp)[1]', 'datetime2'),
victim_process_id = evt.value('(data[@name=""xml_report""]/value/deadlock/victim-list/victimProcess/@id)[1]', 'varchar(50)'),
deadlock_graph_xml = CONVERT(nvarchar(max), evt.query('data[@name=""xml_report""]/value/deadlock'))
FROM
(
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_database_session_targets AS xet
JOIN sys.dm_xe_database_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{DeadlockXeSessionName}'
AND xet.target_name = N'ring_buffer'
pmd.ring_buffer
FROM @PerformanceMonitor_Deadlock AS pmd
) AS rb
CROSS APPLY rb.ring_xml.nodes('RingBufferTarget/event[@name=""database_xml_deadlock_report""]') AS q(evt)
CROSS APPLY rb.ring_buffer.nodes('RingBufferTarget/event[@name=""database_xml_deadlock_report""]') AS q(evt)
WHERE evt.value('(@timestamp)[1]', 'datetime2') > DATEADD(MINUTE, -10, SYSUTCDATETIME())
ORDER BY
evt.value('(@timestamp)[1]', 'datetime2') DESC
OPTION(RECOMPILE);";
}
else
Expand All @@ -298,24 +312,38 @@ Use .query() to get XML with structure intact, then CONVERT to nvarchar(max) */
query = $@"
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

DECLARE
@PerformanceMonitor_Deadlock TABLE
(
ring_buffer xml NOT NULL
);

INSERT
@PerformanceMonitor_Deadlock
(
ring_buffer
)
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_session_targets AS xet
JOIN sys.dm_xe_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{DeadlockXeSessionName}'
AND xet.target_name = N'ring_buffer'
OPTION(RECOMPILE);

SELECT
deadlock_time = evt.value('(@timestamp)[1]', 'datetime2'),
victim_process_id = evt.value('(data[@name=""xml_report""]/value/deadlock/victim-list/victimProcess/@id)[1]', 'varchar(50)'),
deadlock_graph_xml = CONVERT(nvarchar(max), evt.query('data[@name=""xml_report""]/value/deadlock'))
FROM
(
SELECT
ring_xml = TRY_CAST(xet.target_data AS xml)
FROM sys.dm_xe_session_targets AS xet
JOIN sys.dm_xe_sessions AS xes
ON xes.address = xet.event_session_address
WHERE xes.name = N'{DeadlockXeSessionName}'
AND xet.target_name = N'ring_buffer'
pmd.ring_buffer
FROM @PerformanceMonitor_Deadlock AS pmd
) AS rb
CROSS APPLY rb.ring_xml.nodes('RingBufferTarget/event[@name=""xml_deadlock_report""]') AS q(evt)
CROSS APPLY rb.ring_buffer.nodes('RingBufferTarget/event[@name=""xml_deadlock_report""]') AS q(evt)
WHERE evt.value('(@timestamp)[1]', 'datetime2') > DATEADD(MINUTE, -10, SYSUTCDATETIME())
ORDER BY
evt.value('(@timestamp)[1]', 'datetime2') DESC
OPTION(RECOMPILE);";
}

Expand Down