[MySQL][Spider][VP]Spider-2.28 VP-0.17 released

I'm pleased to announce the release of Spider storage engine version 2.28(beta) and Vertical Partitioning storage engine version 0.17(beta).
Spider is a Storage Engine for database sharding.
Vertical Partitioning is a Storage Engine for vertical partitioning for a table.

Please use the following for downloading binary file.

The main changes in this version are following.
- Support parallel searching. ("spider_bgs_mode > 0")
The table using the Spider bundled MySQL and table partitioning performs parallel search of each partition. However, parallel search is not performed in the case which does not make all the partitions applicable to search like sequential search with limit.
- Add server parameter "spider_use_default_database" and "spider_remote_default_database".
These parameter is added for using some replication parameters like "binlog-do-db" on data node. "spider_use_default_database=0" is same of previous versions.
- Add table parameter "access_balance".
This parameter is the weight of load balancing for Spider's redundancy feature.
- Add INFORMATION SCHEMA "spider_alloc_mem".
This INFORMATION SCHEMA plugin adds "information_schema.spider_alloc_mem" table for showing Spider's using memory status. "alloc_mem_count" and "free_mem_count" columns in "information_schema.spider_alloc_mem" table express the count of increasing and decreasing memory, so they do not necessarily become the same.
- Add value of 3 to "quick_mode"(table parameter) and "spider_quick_mode"(server parameter).
"quick_mode=3" is the mode of using temporary table for result set from data node. This mode is useful for searching a huge table.

Spider's management table was changed from previous version and add new plugin, please execute "install_spider.sql" for upgrading.

Vertical Partitioning
- Add UDF paramter "suppress_autoinc".
- Add table parameter "allow_bulk_autoinc" and "allow_different_column_type".
- Add server parameter "vp_allow_bulk_autoinc".

Becomes version 1.1.
- Add server parameter "handlersocket_slow_log", "handlersocket_long_exec_time" and "handlersocket_close_table_interval".
"handlersocket_slow_log" is logging handlersocket request with slow (spend over "handlersocket_long_exec_time" micro second) response into slow log with "slow_query_log=on".
"handlersocket_close_table_interval" is interval of closing table internally for releasing meta data lock for executing like "alter table". You can use this parameter "handlersocket_close_table_interval=0" (doesn't close) for normally and only change this parameter for executing like "alter table".
These parameters are global parameter and you can change them from SQL interface.

Please see "99_change_logs.txt" in the download documents for checking other changes.

Thanks to Takafumi, Yukihiro, Jung, Adrian, leechangyeol, liuyanhong, Hisazumi, Hideyuki, Keisuke for bug reporting.
Thanks to Akira for your advice.


--- 2/17 postscript ---
Spider binaries is updated for fixing getting no result bug of parallel searching. I'm sorry.
Updated version's handlersocket is added the following parameter.
- Add server parameter "handlersocket_get_lock".
This parameter makes handlersocket possible turning off get_lock for write threads. "handlersocket_get_lock=off" is useful for increasing "handlersocket_threads_wr" for some case as using Spider through handlersocket.