Invalid query crashes plyql server + possible caching issues

[l15k4]

Hey,

An invalid query was issued to plyql server from imply data distribution 1.2.1 :

plyql -c 2 -h broker:8082 -i P2Y --json-server 8099

which crashed it :

/usr/local/lib/node_modules/plyql/node_modules/q/q.js:155
                throw e;
                      ^
Error: can not serialize an approximate unique value
    at UniqueAttributeInfo.serialize (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:715:19)
    at DruidExternal.makeSelectorFilter (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:3779:38)
    at DruidExternal.timelessFilterToDruid (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:3833:37)
    at DruidExternal.timelessFilterToDruid (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:3823:37)
    at DruidExternal.makeNativeAggregateFilter (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:4534:30)
    at DruidExternal.applyToAggregation (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:4686:36)
    at DruidExternal.getAggregationsAndPostAggregations (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:4701:22)
    at DruidExternal.getQueryAndPostProcess (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:4978:64)
    at DruidExternal.External.queryValue (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:3170:48)
    at ExternalExpression._computeResolved (/usr/local/lib/node_modules/plyql/node_modules/plywood/build/plywood.js:6788:29)

It was just count query like this :

curl -X POST 'http://host/plyql' -H 'content-type: application/json' -d '{ "sql": "SELECT COUNT(bar) FROM baz" }'

bar is hll field

Isn't this a really critical bug? Server being crashed by such a common query ?

Also what is strange about it is that I was investigating why all of a sudden plyql-server returns empty results which should not be empty. And right after plyql-server docker container restarted it was all good again.

[vogievetsky]

Wops forgot to update the issue. This has been fixed a long time ago. Should be returning a meaningful error now.