[feat](profile) Print changed session var in profile #41016

fe/fe-core/src/main/java/org/apache/doris/common/profile/Profile.java

@@ -108,6 +108,8 @@ public class Profile {
     // Profile size is the size of profile file
     private long profileSize = 0;
 
+    private String changedSessionVarCache = "";
+
     // Need default constructor for read from storage
     public Profile() {}
 
@@ -322,8 +324,9 @@ public String getProfileByLevel() {
         StringBuilder builder = new StringBuilder();
         // add summary to builder
         summaryProfile.prettyPrint(builder);
-        // read execution profile from storage or generate it from memory (during query execution)
+        getChangedSessionVars(builder);
         getExecutionProfileContent(builder);
+        getOnStorageProfile(builder);
 
         return builder.toString();
     }
@@ -367,49 +370,13 @@ public String getProfileBrief() {
         return gson.toJson(rootProfile.toBrief());
     }
 
-    // Read file if profile has been stored to storage.
+    // Return if profile has been stored to storage
     public void getExecutionProfileContent(StringBuilder builder) {
         if (builder == null) {
             builder = new StringBuilder();
         }
 
         if (profileHasBeenStored()) {
-            LOG.info("Profile {} has been stored to storage, reading it from storage", id);
-
-            FileInputStream fileInputStream = null;
-
-            try {
-                fileInputStream = createPorfileFileInputStream(profileStoragePath);
-                if (fileInputStream == null) {
-                    builder.append("Failed to read execution profile from " + profileStoragePath);
-                    return;
-                }
-
-                DataInputStream dataInput = new DataInputStream(fileInputStream);
-                // skip summary profile
-                Text.readString(dataInput);
-                // read compressed execution profile
-                int binarySize = dataInput.readInt();
-                byte[] binaryExecutionProfile = new byte[binarySize];
-                dataInput.readFully(binaryExecutionProfile, 0, binarySize);
-                // decompress binary execution profile
-                String textExecutionProfile = decompressExecutionProfile(binaryExecutionProfile);
-                builder.append(textExecutionProfile);
-                return;
-            } catch (Exception e) {
-                LOG.error("An error occurred while reading execution profile from storage, profile storage path: {}",
-                        profileStoragePath, e);
-                builder.append("Failed to read execution profile from " + profileStoragePath);
-            } finally {
-                if (fileInputStream != null) {
-                    try {
-                        fileInputStream.close();
-                    } catch (Exception e) {
-                        LOG.warn("Close profile {} failed", profileStoragePath, e);
-                    }
-                }
-            }
-
             return;
         }
 
@@ -449,8 +416,9 @@ public void setSummaryProfile(SummaryProfile summaryProfile) {
         this.summaryProfile = summaryProfile;
     }
 
-    public void releaseExecutionProfile() {
+    public void releaseMemory() {
         this.executionProfiles.clear();
+        this.changedSessionVarCache = "";
     }
 
     public boolean shouldStoreToStorage() {
@@ -583,6 +551,7 @@ public void writeToStorage(String systemProfileStorageDir) {
 
             // store execution profiles as string
             StringBuilder build = new StringBuilder();
+            getChangedSessionVars(build);
             getExecutionProfileContent(build);
             byte[] buf = compressExecutionProfile(build.toString());
             dataOutputStream.writeInt(buf.length);
@@ -651,4 +620,65 @@ public boolean shouldBeRemoveFromMemory() {
 
         return true;
     }
+
+    public void setChangedSessionVar(String changedSessionVar) {
+        this.changedSessionVarCache = changedSessionVar;
+    }
+
+    private void getChangedSessionVars(StringBuilder builder) {
+        if (builder == null) {
+            builder = new StringBuilder();
+        }
+        if (profileHasBeenStored()) {
+            return;
+        }
+
+        builder.append("\nChanged Session Variables:\n");
+        builder.append(changedSessionVarCache);
+        builder.append("\n");
+    }
+
+    private void getOnStorageProfile(StringBuilder builder) {
+        if (!profileHasBeenStored()) {
+            return;
+        }
+
+        LOG.info("Profile {} has been stored to storage, reading it from storage", id);
+
+        FileInputStream fileInputStream = null;
+
+        try {
+            fileInputStream = createPorfileFileInputStream(profileStoragePath);
+            if (fileInputStream == null) {
+                builder.append("Failed to read execution profile from " + profileStoragePath);
+                return;
+            }
+
+            DataInputStream dataInput = new DataInputStream(fileInputStream);
+            // skip summary profile
+            Text.readString(dataInput);
+            // read compressed execution profile
+            int binarySize = dataInput.readInt();
+            byte[] binaryExecutionProfile = new byte[binarySize];
+            dataInput.readFully(binaryExecutionProfile, 0, binarySize);
+            // decompress binary execution profile
+            String textExecutionProfile = decompressExecutionProfile(binaryExecutionProfile);
+            builder.append(textExecutionProfile);
+            return;
+        } catch (Exception e) {
+            LOG.error("An error occurred while reading execution profile from storage, profile storage path: {}",
+                    profileStoragePath, e);
+            builder.append("Failed to read execution profile from " + profileStoragePath);
+        } finally {
+            if (fileInputStream != null) {
+                try {
+                    fileInputStream.close();
+                } catch (Exception e) {
+                    LOG.warn("Close profile {} failed", profileStoragePath, e);
+                }
+            }
+        }
+
+        return;
+    }
 }

fe/fe-core/src/main/java/org/apache/doris/common/util/DebugUtil.java

@@ -26,6 +26,7 @@
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.text.DecimalFormat;
+import java.util.List;
 import java.util.UUID;
 
 public class DebugUtil {
@@ -177,4 +178,62 @@ public static String getStackTrace(Exception e) {
         e.printStackTrace(new PrintWriter(sw));
         return sw.toString();
     }
+
+    public static String prettyPrintChangedSessionVar(List<List<String>> nestedList) {
+        if (nestedList == null || nestedList.isEmpty()) {
+            return "";
+        }
+
+        StringBuilder output = new StringBuilder();
+
+        // Assuming each inner list has exactly 3 columns
+        int[] columnWidths = new int[3];
+
+        // Calculate the maximum width of each column
+        // First consider the header widths: "VarName", "CurrentValue", "DefaultValue"
+        String[] headers = {"VarName", "CurrentValue", "DefaultValue"};
+        for (int i = 0; i < headers.length; i++) {
+            columnWidths[i] = headers[i].length();  // Initialize with header length
+        }
+
+        // Update column widths based on data
+        for (List<String> row : nestedList) {
+            for (int i = 0; i < row.size(); i++) {
+                columnWidths[i] = Math.max(columnWidths[i], row.get(i).length());
+            }
+        }
+
+        // Build the table header
+        for (int i = 0; i < headers.length; i++) {
+            output.append(String.format("%-" + columnWidths[i] + "s", headers[i]));
+            if (i < headers.length - 1) {
+                output.append(" | ");  // Separator between columns
+            }
+        }
+        output.append("\n");  // Newline after the header
+
+        // Add a separator line for better readability (optional)
+        for (int i = 0; i < headers.length; i++) {
+            output.append(String.format("%-" + columnWidths[i] + "s", Strings.repeat("-", columnWidths[i])));
+            if (i < headers.length - 1) {
+                output.append("-|-");  // Separator between columns
+            }
+        }
+        output.append("\n");  // Newline after the separator
+
+        // Build the table body with proper alignment based on column widths
+        for (List<String> row : nestedList) {
+            for (int i = 0; i < row.size(); i++) {
+                String element = row.get(i);
+                // Pad with spaces if the element is shorter than the column width
+                output.append(String.format("%-" + columnWidths[i] + "s", element));
+                if (i < row.size() - 1) {
+                    output.append(" | ");  // Separator between columns
+                }
+            }
+            output.append("\n");  // Newline after each row
+        }
+
+        return output.toString();
+    }
 }

fe/fe-core/src/main/java/org/apache/doris/common/util/ProfileManager.java

@@ -687,7 +687,7 @@ private void writeProfileToStorage() {
                     for (ExecutionProfile executionProfile : profileElement.profile.getExecutionProfiles()) {
                         this.queryIdToExecutionProfiles.remove(executionProfile.getQueryId());
                     }
-                    profileElement.profile.releaseExecutionProfile();
+                    profileElement.profile.releaseMemory();
                 }
             } finally {
                 writeLock.unlock();

fe/fe-core/src/main/java/org/apache/doris/qe/StmtExecutor.java

@@ -673,6 +673,8 @@ private void executeByNereids(TUniqueId queryId) throws Exception {
         context.setQueryId(queryId);
         context.setStartTime();
         profile.getSummaryProfile().setQueryBeginTime();
+        List<List<String>> changedSessionVar = VariableMgr.dumpChangedVars(context.getSessionVariable());
+        profile.setChangedSessionVar(DebugUtil.prettyPrintChangedSessionVar(changedSessionVar));
         context.setStmtId(STMT_ID_GENERATOR.incrementAndGet());
 
         parseByNereids();

fe/fe-core/src/main/java/org/apache/doris/qe/VariableMgr.java

@@ -800,6 +800,42 @@ public int compare(List<String> o1, List<String> o2) {
         return changedRows;
     }
 
+    public static List<List<String>> dumpChangedVars(SessionVariable sessionVar) {
+        // Hold the read lock when session dump, because this option need to access global variable.
+        rlock.lock();
+        List<List<String>> changedRows = Lists.newArrayList();
+        try {
+            for (Map.Entry<String, VarContext> entry : ctxByDisplayVarName.entrySet()) {
+                VarContext ctx = entry.getValue();
+                List<String> row = Lists.newArrayList();
+                String varName = entry.getKey();
+                String curValue = getValue(sessionVar, ctx.getField());
+                String defaultValue = ctx.getDefaultValue();
+                if (VariableVarConverters.hasConverter(varName)) {
+                    try {
+                        defaultValue = VariableVarConverters.decode(varName, Long.valueOf(defaultValue));
+                        curValue = VariableVarConverters.decode(varName, Long.valueOf(curValue));
+                    } catch (DdlException e) {
+                        LOG.warn("Decode session variable {} failed, reason: {}", varName, e.getMessage());
+                    }
+                }
+
+                if (curValue.equals(defaultValue)) {
+                    continue;
+                }
+
+                row.add(varName);
+                row.add(curValue);
+                row.add(defaultValue);
+                changedRows.add(row);
+            }
+        } finally {
+            rlock.unlock();
+        }
+
+        return changedRows;
+    }
+
     @Retention(RetentionPolicy.RUNTIME)
     public @interface VarAttr {
         // Name in show variables and set statement;