ClickHouse · kssenii · Oct 15, 2024 · Sep 26, 2024 · Oct 1, 2024 · Oct 1, 2024
diff --git a/docs/en/operations/opentelemetry.md b/docs/en/operations/opentelemetry.md
@@ -31,6 +31,10 @@ The table must be enabled in the server configuration, see the `opentelemetry_sp
 
 The tags or attributes are saved as two parallel arrays, containing the keys and values. Use [ARRAY JOIN](../sql-reference/statements/select/array-join.md) to work with them.
 
+## Log-query-settings
+
+ClickHouse allows you to log changes to query settings during query execution. When enabled, any modifications made to query settings will be recorded in the OpenTelemetry span log. This feature is particularly useful in production environments for tracking configuration changes that may affect query performance.
+
 ## Integration with monitoring systems
 
 At the moment, there is no ready tool that can export the tracing data from ClickHouse to a monitoring system.

diff --git a/docs/en/operations/settings/settings.md b/docs/en/operations/settings/settings.md
@@ -540,6 +540,14 @@ Default value: 0
 
 Allow non-const timezone arguments in certain time-related functions like toTimeZone(), fromUnixTimestamp*(), snowflakeToDateTime*()
 
+## log_query_settings {#log-query-settings}
+
+Type: Bool
+
+Default value: 1
+
+Log query settings into the query_log and opentelemetry_span_log.
+
 ## allow_nondeterministic_mutations {#allow_nondeterministic_mutations}
 
 Type: Bool

diff --git a/src/Core/Settings.cpp b/src/Core/Settings.cpp
@@ -2700,7 +2700,7 @@ The maximum read speed in bytes per second for particular backup on server. Zero
 Log query performance statistics into the query_log, query_thread_log and query_views_log.
 )", 0) \
     M(Bool, log_query_settings, true, R"(
-Log query settings into the query_log.
+Log query settings into the query_log and OpenTelemetry span log.
 )", 0) \
     M(Bool, log_query_threads, false, R"(
 Setting up query threads logging.
@@ -6200,6 +6200,16 @@ std::vector<std::string_view> Settings::getUnchangedNames() const
     return setting_names;
 }
 
+std::vector<std::string_view> Settings::getChangedNames() const
+{
+    std::vector<std::string_view> setting_names;
+    for (const auto & setting : impl->allChanged())
+    {
+        setting_names.emplace_back(setting.getName());
+    }
+    return setting_names;
+}
+
 void Settings::dumpToSystemSettingsColumns(MutableColumnsAndConstraints & params) const
 {
     MutableColumns & res_columns = params.res_columns;

diff --git a/src/Core/Settings.h b/src/Core/Settings.h
@@ -134,6 +134,7 @@ struct Settings
     std::vector<std::string_view> getAllRegisteredNames() const;
     std::vector<std::string_view> getChangedAndObsoleteNames() const;
     std::vector<std::string_view> getUnchangedNames() const;
+    std::vector<std::string_view> getChangedNames() const;
 
     void dumpToSystemSettingsColumns(MutableColumnsAndConstraints & params) const;
     void dumpToMapColumn(IColumn * column, bool changed_only = true) const;

diff --git a/src/Interpreters/executeQuery.cpp b/src/Interpreters/executeQuery.cpp
@@ -5,6 +5,7 @@
 #include <Common/MemoryTrackerBlockerInThread.h>
 #include <Common/SensitiveDataMasker.h>
 #include <Common/FailPoint.h>
+#include <Common/FieldVisitorToString.h>
 
 #include <Interpreters/AsynchronousInsertQueue.h>
 #include <Interpreters/Cache/QueryCache.h>
@@ -564,6 +565,25 @@ void logQueryFinish(
         query_span->addAttributeIfNotZero("clickhouse.written_rows", elem.written_rows);
         query_span->addAttributeIfNotZero("clickhouse.written_bytes", elem.written_bytes);
         query_span->addAttributeIfNotZero("clickhouse.memory_usage", elem.memory_usage);
+
+        if (context)
+        {
+            std::string user_name = context->getUserName();
+            query_span->addAttribute("clickhouse.user", user_name);
+        }
+
+        if (settings[Setting::log_query_settings])
+        {
+            auto changed_settings_names = settings.getChangedNames();
+            for (const auto & name : changed_settings_names)
+            {
+                Field value = settings.get(name);
+                String value_str = convertFieldToString(value);
+
+                query_span->addAttribute(fmt::format("clickhouse.setting.{}", name), value_str);
+
+            }
+        }
         query_span->finish();
     }
 }

diff --git a/tests/queries/0_stateless/02421_simple_queries_for_opentelemetry.reference b/tests/queries/0_stateless/02421_simple_queries_for_opentelemetry.reference
@@ -2,3 +2,5 @@
 {"query":"show databases format Null\n  "}
 {"query":"insert into opentelemetry_test values","read_rows":"3","written_rows":"3"}
 {"query":"select * from opentelemetry_test format Null\n  ","read_rows":"3","written_rows":""}
+{"query":"SELECT * FROM opentelemetry_test FORMAT Null\n  ","read_rows":"3","written_rows":""}
+{"min_compress_block_size":"present","max_block_size":"present","max_execution_time":"present"}
diff --git a/tests/queries/0_stateless/02421_simple_queries_for_opentelemetry.sh b/tests/queries/0_stateless/02421_simple_queries_for_opentelemetry.sh
@@ -44,6 +44,37 @@ ${CLICKHOUSE_CLIENT} -q "
     ;"
 }
 
+function check_query_settings()
+{
+result=$(${CLICKHOUSE_CLIENT} -q "
+    SYSTEM FLUSH LOGS;
+    SELECT attribute['clickhouse.setting.min_compress_block_size'],
+           attribute['clickhouse.setting.max_block_size'],
+           attribute['clickhouse.setting.max_execution_time']
+    FROM system.opentelemetry_span_log
+    WHERE finish_date                      >= yesterday()
+    AND   operation_name                   = 'query'
+    AND   attribute['clickhouse.query_id'] = '${1}'
+    FORMAT JSONEachRow;
+  ")
+
+    local min_present="not found"
+    local max_present="not found"
+    local execution_time_present="not found"
+
+    if [[ $result == *"min_compress_block_size"* ]]; then
+       min_present="present"
+    fi
+    if [[ $result == *"max_block_size"* ]]; then
+       max_present="present"
+    fi
+    if [[ $result == *"max_execution_time"* ]]; then
+       execution_time_present="present"
+    fi
+
+    echo "{\"min_compress_block_size\":\"$min_present\",\"max_block_size\":\"$max_present\",\"max_execution_time\":\"$execution_time_present\"}"
+}
+
 #
 # Set up
 #
@@ -73,6 +104,11 @@ query_id=$(${CLICKHOUSE_CLIENT} -q "select generateUUIDv4()");
 execute_query $query_id 'select * from opentelemetry_test format Null'
 check_query_span $query_id
 
+# Test 5: A normal select query with a setting
+query_id=$(${CLICKHOUSE_CLIENT} -q "SELECT generateUUIDv4() SETTINGS max_execution_time=3600")
+execute_query "$query_id" 'SELECT * FROM opentelemetry_test FORMAT Null'
+check_query_span "$query_id"
+check_query_settings "$query_id" "max_execution_time"
 
 #
 # Tear down