The Impala CatalogService manages the caching and dissemination of cluster-wide metadata.
The CatalogService combines the metadata from the Hive Metastore, the NameNode,
and potentially additional sources in the future. The CatalogService uses the
StateStore to broadcast metadata updates across the cluster.
The CatalogService also directly handles executing metadata updates request from
impalad servers (DDL requests). It exposes a Thrift interface to allow impalads to
directly connect execute their DDL operations.
The CatalogService has two main components - a C++ server that implements StateStore
integration, Thrift service implementiation, and exporting of the debug webpage/metrics.
The other main component is the Java Catalog that manages caching and updating of of all
the metadata. For each StateStore heartbeat, a delta of all metadata updates is broadcast
to the rest of the cluster.
Some Notes On the Changes
---
* The metadata is all sent as thrift structs. To do this all catalog objects (Tables/Views,
Databases, UDFs) have thrift struct to represent them. These are sent with each statestore
delta update.
* The existing Catalog class has been seperated into two seperate sub-classes. An
ImpladCatalog and a CatalogServiceCatalog. See the comments on those classes for more
details.
What is working:
* New CatalogService created
* Working with statestore delta updates and latest UDF changes
* DDL performed on Node 1 is now visible on all other nodes without a "refresh".
* Each DDL operation against the Catalog Service will return the catalog version that
contains the change. An impalad will wait for the statestore heartbeat that contains this
version before returning from the DDL comment.
* All table types (Hbase, Hdfs, Views) getting their metadata propagated properly
* Block location information included in CS updates and used by Impalads
* Column and table stats included in CS updates and used by Impalads
* Query tests are all passing
Still TODO:
* Directly return catalog object metadata from DDL requests
* Poll the Hive Metastore to detect new/dropped/modified tables
* Reorganize the FE code for the Catalog Service. I don't think we want everything in the
same JAR.
Change-Id: I8c61296dac28fb98bcfdc17361f4f141d3977eda
Reviewed-on: http://gerrit.ent.cloudera.com:8080/601
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: Lenni Kuff <lskuff@cloudera.com>
Fixed cost estimation of union queries and exchange nodes.
Fixed propagation of stats through cloning of exprs and plan nodes.
Fixed propagation of expr stats to slots they are materialized into (e.g., grouping columns in multi-level aggs).
Improved explain output for constant selects.
Change-Id: I96d1652c00d48e4093b85ae7fc8bad28d74b8b81
Reviewed-on: http://gerrit.ent.cloudera.com:8080/547
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: Alex Behm <alex.behm@cloudera.com>
This patch also adds a number of improvements to NativeUdfExpr. Highlights include:
* Correctly handling the lowering of AnyVal struct types (required for ABI compatibility)
* A rudimentary library cache for reusing handles produced by dlopen
* More complicated test cases
Change-Id: Iab9acdd7d7c4308e5d7ee3210f21b033fda5a195
Reviewed-on: http://gerrit.ent.cloudera.com:8080/540
Tested-by: jenkins
Reviewed-by: Skye Wanderman-Milne <skye@cloudera.com>
Tested-by: Skye Wanderman-Milne <skye@cloudera.com>
I looked around some and I think having create/drop/show [aggregate] function
seems reasonable and extends nicely for UDTs.
The create aggregate function can accept a lot of arguments. The non-essential one, I
went with resolving them by name rather than position (i.e. argName="value"). I think
this is better for the user than specifying it by position.
The grammar is:
CREATE AGGREGATE <name>(<arg_types>) RETURNS <type> [INTERMEDIATE <type>]
LOCATION '/path' UpdateFn='Fn' [comment='comment']
[SerializeFn='symbol'] [MergeFn='symbol'] [InitFn='symbol'] [FinalizeFn='symbol']
The optional args at the end can be in any order. If the other symbols are not
specified, we derive them from the UpdateFn symbol that's required. The analyzer
would try to figure it out and fail if we can't find the derived symbol in the binary.
The simplest example would be:
CREATE AGGREGATE FUNCTION count(float) RETURNS BIGINT LOCATION '/path'
UpdateFn='CountUpdateFn';
In which case we assume the intermediate type is the return type and the other functions
are called 'CountInitFn', 'CountSerializeFn', 'CountMergeFn' 'CountFinalizeFn'.
Change-Id: Iefc5741293050f5b295df28e9d1a7d039ead8675
Reviewed-on: http://gerrit.ent.cloudera.com:8080/513
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Nong Li <nong@cloudera.com>
OVERWRITE
INSERT OVERWRITE into an unpartitioned table is supposed to remove all
data files from the root. This should not include hidden files or
directories. This patch excludes hidden files from deletion, and adds a
test case.
Partition directories are still removed in their entirety: the cost of
statting a large number of files and directories rather than issuing a
single "rm -rf" outweighs the benefits of preserving hidden files for
now.
Hive does not preserve hidden files in either configuration.
Change-Id: Ia73e55e011c26c88f14745075210cf359764e3c1
Reviewed-on: http://gerrit.ent.cloudera.com:8080/418
Tested-by: jenkins
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
This change adds Impala DDL support for creation of AVRO tables.
Additionally, it add Impala support for CREATE and ALTER SERDEPROPERTIES
which are used when creating Avro backed tables. This syntax is not
exactly the same as the Hive support since it introduces a new
fileformat (AVROFILE) that implies the needed Serialization library,
input format, and output format.
Change-Id: I5047e419198a89599e9d014fdedfee1a20437a7d
Reviewed-on: http://gerrit.ent.cloudera.com:8080/464
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: Lenni Kuff <lskuff@cloudera.com>
Our data generation doesn't appear to fully support comments in the
base table name section. This fixes the data generation, but we should
follow on by improving our comment support in the framework.
Change-Id: I68274bd98d5b0d54868d6c80b7137a59e7329229
Reviewed-on: http://gerrit.ent.cloudera.com:8080/465
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Lenni Kuff <lskuff@cloudera.com>
Doing it this way makes sure we don't bail early on the Close path
which is rarely the right thing to do. This found a few places where
we were not doing proper cleanup because of this.
Change-Id: Ie663c68398c14589b5cbc1bd980644b0b10fd865
Reviewed-on: http://gerrit.ent.cloudera.com:8080/373
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Nong Li <nong@cloudera.com>
Changes MemLimit to MemTracker:
- the limit is optional
- it also records a label and an optional parent
- Consume() and Release() also update the ancestors and there's also a new
AnyLimitExceeded(), which also checks the ancestors
- the consumption counter is a HighwaterMarkCounter and can optionally be created
as part of a profile
Each fragment instance now has a MemTracker that is part of a 3-level
hierarchy: process, query, fragment instance.
Change-Id: I5f580f4956fdf07d70bd9a6531032439aaf0fd07
Reviewed-on: http://gerrit.ent.cloudera.com:8080/339
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Nong Li <nong@cloudera.com>
This is an experimental implementation of external sorting. This patch includes the following additions:
(1) creation and implementation of the Sorter interface, which can sort Impala Tuples.
(2) normalization of Tuples to allow memcmp-able sorting.
(3) a testing framework for the Sorter,
(4) a benchmark to compare the current state of the Sorter with other sorts,
(5) an implementation of a Vector which can store data whose size is only known at runtime,
(6) a sorting algorithm (basically a dumbed down STL sort) which can operate over such a vector,
(7) implementation of a simple in-memory Merger, and
(8) logic to stream blocks of memory in and out of memory for the actual external merging.
I have a local branch for experimental optimizations and benchmarking -- this should be considered
a "basic", working sort.
The following optimizations have been implemented:
(i) Optionally extracting keys instead of writing them in place.
(ii) Optionally opportunistically parallelize run building (sorting & prepare for output).
(iii) Maximize disk IO and minimize buffer recycling by writing buffers out, but also keeping
them in memory until right when they're needed.
(iv) Prepare auxililary data backwards so the buffers can be released as we go, and still
go out in an order which preserves the first buffers of the run.
(v) Always merge maximum number of runs at a time, taking from the next merge level if
available.
Change-Id: I1d7304d54d73152da929b1efffc1e851e5fb8fd4
Reviewed-on: http://gerrit.ent.cloudera.com:8080/126
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Aaron Davidson <aaron.davidson@cloudera.com>
Implements a group_concat() function which concatenates all the values in a group together.
The format is group_concat(str_col, [separator]). The default separator is ', '. NULLs
are ignored.
Change-Id: If152df6f528401117dba81d66ef691bfb548cc7d
Reviewed-on: http://gerrit.ent.cloudera.com:8080/117
Reviewed-by: Aaron Davidson <aaron.davidson@cloudera.com>
Tested-by: Aaron Davidson <aaron.davidson@cloudera.com>
This adds support for CREATE TABLE AS SELECT to Impala. It supports all functionality a
regular CREATE TABLE statement includes, except it does not allow for for specifying
partition columns. Hive also has this limitation and it wouldn't be too hard to support
in the future.
Change-Id: I4ca3c3b8f1576441b8bb5ed9dc521d7dfa96ab74
Reviewed-on: http://gerrit.ent.cloudera.com:8080/157
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: Lenni Kuff <lskuff@cloudera.com>
I tried to investigate the jenkins issue where we weren't returning any rows.
I setup the cluster on that box manually and noticed there weren't any results
because the store_sales table was empty. Refresh did not fix. This looks like
a data loading issue. Adding this test would make discovering this like this
much easier.
Change-Id: I8ccddd43892b279d506371b9de717629815c6a08
Reviewed-on: http://gerrit.ent.cloudera.com:8080/260
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Nong Li <nong@cloudera.com>
Split out the encoder/type for parquet reader/writer. I think this puts us
in a better place to support future encodings.
On the tpch lineitem table, the results are:
Before:
BytesWritten: 236.45 MB
Per Column Sizes:
l_comment: 75.71 MB
l_commitdate: 8.64 MB
l_discount: 11.19 MB
l_extendedprice: 33.02 MB
l_linenumber: 4.56 MB
l_linestatus: 869.98 KB
l_orderkey: 8.99 MB
l_partkey: 27.02 MB
l_quantity: 11.58 MB
l_receiptdate: 8.65 MB
l_returnflag: 1.40 MB
l_shipdate: 8.65 MB
l_shipinstruct: 1.45 MB
l_shipmode: 2.17 MB
l_suppkey: 21.91 MB
l_tax: 10.68 MB
After:
BytesWritten: 198.63 MB (84%)
Per Column Sizes:
l_comment: 75.71 MB (100%)
l_commitdate: 8.64 MB (100%)
l_discount: 2.89 MB (25.8%)
l_extendedprice: 33.13 MB (100.33%)
l_linenumber: 1.50 MB (32.89%)
l_linestatus: 870.26 KB (100.032%)
l_orderkey: 9.18 MB (102.11%)
l_partkey: 27.10 MB (100.29%)
l_quantity: 4.32 MB (37.31%)
l_receiptdate: 8.65 MB (100%)
l_returnflag: 1.40 MB (100%)
l_shipdate: 8.65 MB (100%)
l_shipinstruct: 1.45 MB (100%)
l_shipmode: 2.17 MB (100%)
l_suppkey: 10.11 MB (46.14%)
l_tax: 2.89 MB (27.06%)
The table is overall 84% as big (i.e. 16% smaller). A few columns got marginally
bigger. If the file filled the 1 GB, I'd expect the overhead to decrease even
more.
The restructuring to use a virtual call doesn't seem to change things much and
will go away when we codegen the scanner.
Here's what they look like with this patch (note this is on the before data files,
so only string cols are dictionary encoded).
Before query times:
Insert Time: 8.5 sec
select *: 2.3 sec
select avg(l_orderkey): .33 sec
After query times:
Insert Time: 9.5 sec <-- Longer due to doing dictionary encoding
select *: 2.4 sec <-- kind of noisy, possibly a slight slow down
select avg(l_orderkey): .33 sec
Change-Id: I213fdca1bb972cc200dc0cd9fb14b77a8d36d9e6
Reviewed-on: http://gerrit.ent.cloudera.com:8080/238
Tested-by: jenkins <kitchen-build@cloudera.com>
Reviewed-by: Skye Wanderman-Milne <skye@cloudera.com>