[IMPALA-9641] Query hang when containing alias names as empty backticks

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 3.4.0
• Fix Version/s: Impala 4.0.0
• Component/s: Frontend
• Labels: hang
• Target Version: Impala 4.0.0
• Epic Color: ghx-label-5
• Assignee: Tamas Mate
• Reporter: Quanlong Huang
• Created: 10/Apr/20 03:24
• Updated: 19/Sep/23 07:23
• Resolved: 09/Feb/21 09:06

Description

The following query will hang in an infinite loop:

select 1 as "``";

Stacktrace of its compiler thread:

"Thread-19" #34 prio=5 os_prio=0 tid=0x0000000012fc0000 nid=0x5514 runnable [0x00007f2abda41000]
   java.lang.Thread.State: RUNNABLE
        at java.io.FileOutputStream.writeBytes(Native Method)
        at java.io.FileOutputStream.write(FileOutputStream.java:326)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
        - locked <0x00000005cc90f7b8> (a java.io.BufferedOutputStream)
        at java.io.PrintStream.write(PrintStream.java:482)
        - locked <0x00000005cc90f798> (a java.io.PrintStream)
        at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
        at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)
        at sun.nio.cs.StreamEncoder.flushBuffer(StreamEncoder.java:104)
        - locked <0x00000005cc90f8d8> (a java.io.OutputStreamWriter)
        at java.io.OutputStreamWriter.flushBuffer(OutputStreamWriter.java:185)
        at java.io.PrintStream.write(PrintStream.java:527)
        - locked <0x00000005cc90f798> (a java.io.PrintStream)
        at java.io.PrintStream.print(PrintStream.java:669)
        at java.io.PrintStream.println(PrintStream.java:806)
        - locked <0x00000005cc90f798> (a java.io.PrintStream)
        at org.antlr.runtime.BaseRecognizer.emitErrorMessage(BaseRecognizer.java:344)
        at org.antlr.runtime.BaseRecognizer.displayRecognitionError(BaseRecognizer.java:194)
        at org.antlr.runtime.Lexer.reportError(Lexer.java:261)
        at org.antlr.runtime.Lexer.nextToken(Lexer.java:103)
        at org.apache.impala.analysis.ToSqlUtils.hiveNeedsQuotes(ToSqlUtils.java:145)
        at org.apache.impala.analysis.ToSqlUtils.getIdentSql(ToSqlUtils.java:199)
        at org.apache.impala.analysis.SlotRef.<init>(SlotRef.java:58)
        at org.apache.impala.analysis.SelectStmt$SelectAnalyzer.analyzeSelectClause(SelectStmt.java:283)
        at org.apache.impala.analysis.SelectStmt$SelectAnalyzer.analyze(SelectStmt.java:215)
        at org.apache.impala.analysis.SelectStmt$SelectAnalyzer.access$100(SelectStmt.java:199)
        at org.apache.impala.analysis.SelectStmt.analyze(SelectStmt.java:192)
        at org.apache.impala.analysis.AnalysisContext.analyze(AnalysisContext.java:473)
        at org.apache.impala.analysis.AnalysisContext.analyzeAndAuthorize(AnalysisContext.java:437)
        at org.apache.impala.service.Frontend.doCreateExecRequest(Frontend.java:1530)
        at org.apache.impala.service.Frontend.getTExecRequest(Frontend.java:1497)
        at org.apache.impala.service.Frontend.createExecRequest(Frontend.java:1467)
        at org.apache.impala.service.JniFrontend.createExecRequest(JniFrontend.java:154)

org.antlr.runtime.Lexer keeps emitting the same error message to stderr (which is redirected to impalad.ERROR):

line 1:0 rule Identifier failed predicate: {allowQuotedId()}?
line 1:0 rule Identifier failed predicate: {allowQuotedId()}?
line 1:0 rule Identifier failed predicate: {allowQuotedId()}?

Issue Links

• is related to: IMPALA-9921 Parse errors in ToSqlUtils.hiveNeedsQuotes should not be printed to impalad.ERROR