[DRILL-4175] IOBE may occur in Calcite RexProgramBuilder when queries are submitted concurrently

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.8.0

Environment

distribution

• Flags: Important
• Assignee: Unassigned
• Reporter: huntersjm
• Reviewer: Krystal
• Created: 09/Dec/15 03:46
• Updated: 26/Aug/16 15:47
• Resolved: 18/Jul/16 22:25

Description

I queryed a sql just like `selelct v from table limit 1`,I get a error:

org.apache.drill.common.exceptions.UserException: SYSTEM ERROR: IndexOutOfBoundsException: Index: 68, Size: 67

After debug, I found there is a bug in calcite parse:
first we look line 72 in org.apache.calcite.rex.RexProgramBuilder

   registerInternal(RexInputRef.of(i, fields), false);

there we get RexInputRef from RexInputRef.of, and it has a method named createName(int idex), here NAMES is SelfPopulatingList.class. SelfPopulatingList.class describe as Thread-safe list, but in fact it is Thread-unsafe. when NAMES.get(index) is called distributed, it gets a error. We hope SelfPopulatingList.class to be {$0 $1 $2 ....$n}, but when it called distributed, it may be {$0,$1...$29,$30...$59,$30,$31...$59...}.
We see method registerInternal

private RexLocalRef registerInternal(RexNode expr, boolean force) {
expr = simplify(expr);

    RexLocalRef ref;
    final Pair<String, String> key;
    if (expr instanceof RexLocalRef) {
      key = null;
      ref = (RexLocalRef) expr;
    } else {
      key = RexUtil.makeKey(expr);
      ref = exprMap.get(key);
    }
    if (ref == null) {
      if (validating) {
        validate(
            expr,
            exprList.size());
      }

Here makeKey(expr) hope to get different key, however it get same key, so addExpr(expr) called less, in this method

RexLocalRef ref;
    final int index = exprList.size();
    exprList.add(expr);
    ref =
        new RexLocalRef(
            index,
            expr.getType());
    localRefList.add(ref);
    return ref;

localRefList get error size, so in line 939,

final RexLocalRef ref = localRefList.get(index);

throw IndexOutOfBoundsException

bugfix:
We can't change origin code of calcite before they fix this bug, so we can init NAMEs in RexLocalRef on start. Just add

RexInputRef.createName(2048);

on Bootstrap.

Issue Links

• depends upon: CALCITE-1009 SelfPopulatingList is not thread-safe
• depends upon: DRILL-3993 Rebase Drill on Calcite master branch
• relates to: CALCITE-440 Non-deterministic IndexOutOfBoundsException in PlannerTest.testBushy5