Remove ORACLE from the (session) sql_mode in connections made with sql
service to run init queries
The connection is new and the global variable value takes effect
rather than the session value from the caller of spider_db_init.
This should fix certain CI builds where the spider suite test files
and the main suite test files do not follow the same relative paths
relations as the mariadb source.
$MYSQLD_CMD uses .1 as the defaults-group-suffix, which could cause
the use of the default port (3306) or socket, which will fail in
environment where these defaults are already in use by another server.
Adding an extra --defaults-group-suffix=.1.1 does not help, because
the first flag wins.
So we use $MYSQLD_LAST_CMD instead, which uses the correct suffix.
The extra innodb buffer pool warning is irrelevant to the goal of the
test (running --wsrep-recover with --plug-load-add=ha_spider should
not cause hang)
Fix spider init bugs (MDEV-22979, MDEV-27233, MDEV-28218) while
preventing regression on old ones (MDEV-30370, MDEV-29904)
Two things are changed:
First, Spider initialisation is made fully synchronous, i.e. it no
longer happens in a background thread. Adapted from the original fix
by nayuta for MDEV-27233. This change itself would cause failure when
spider is initialised early, by plugin-load-add, due to dependency on
Aria and udf function creation, which are fixed in the second and
third parts below. Requires SQL Service, thus porting earlier versions
requires MDEV-27595
Second, if spider is initialised before udf_init(), create udf by
inserting into `mysql.func`, otherwise do it by `CREATE FUNCTION` as
usual. This change may be generalised in MDEV-31401.
Also factor out some clean-up queries from deinit_spider.inc for use
of spider init tests.
A minor caveat is that early spider initialisation will fail if the
server is bootstrapped for the first time, due to missing `mysql`
database which needs to be created by the bootstrap script.
Removing procedures that were created and dropped during init.
This also fixes a race condition where mtr test with
plugin-load-add=ha_spider.so causes post test check to fail as it
expects the procedures to still be there.
There are several plugins in ha_spider: spider, spider_alloc_mem,
spider_wrapper_protocols, spider_rewrite etc.
INSTALL PLUGIN foo SONAME ha_spider causes all the other ones to be
installed by the init queries where foo is any of the plugins.
This introduces unnecessary complexiy. For example it reads
mysql.plugins to find all other plugins, causing the hack of moving
spider plugin init to a separate thread.
To install all spider related plugins, install soname ha_spider should
be used instead.
This also fixes spurious rows in mysql.plugin when installing say only
the spider plugin with `plugin-load-add=SPIDER=ha_spider.so`:
select * from mysql.plugin;
name dl
spider_alloc_mem ha_spider.so # should not be here
spider_wrapper_protocols ha_spider.so # should not be here
Adapted from part of the reverted commit
c160a115b8.
This avoids the scenario in MDEV-32849, when the unlock happens after
the connection has been freed, say in rollback. This is done in 10.5+
after the commit a26700cca5.
It may or may not prevent potential other scenarios where spider has
locked something, then for some reason the statement needs to be
rolled back and spider frees the connection, and then spider proceeds
to use the freed connection. But at least we fix the regression
introduced by MDEV-30014 to 10.4 and bring 10.4 closer in parity with
10.5+.
We remove the call to update spider persistent table stats (sts/crd)
in spider_free_share(). This prevents spider from opening and closing
further tables during close(), which fixes the following issues:
MDEV-28739: ha_spider::close() is called during tdc_start_shutdown(),
which is called after query_cache_destroy(). Closing the sts/crd Aria
tables will trigger a call to Query_cache::invalidate_table(), which
will attempt to use the query cache mutex structure_guard_mutex
destroyed previously.
MDEV-29421: during ha_spider::close(), spider_free_share() could
trigger another spider_free_share() through updating sts/crd table,
because open_table() calls tc_add_table(), which could trigger another
ha_spider::close()...
Since spider sts/crd system tables are only updated here, there's no
use for these tables any more, and we remove all uses of these tables
too.
The removal should not cause any performance issue, as in memory
spider table stats are only updated based on a time
interval (spider_sts_interval and spider_crd_interval), which defaults
to 10 seconds. It should not affect accuracy either, due to the
infrequency of server restart. And inaccurate stats are not a problem
for optimizer anyway.
To be on the safe side, we defer the removal of the spider sts/crd
tables themselves to future.
This will avoid issues like MDEV-32486
IDs used in
- spider_alloc_calc_mem_init()
- spider_string::init_calc_mem()
- spider_malloc()
- spider_bulk_alloc_mem()
- spider_bulk_malloc()
This fixes MDEV-30014, MDEV-29456, MDEV-29667, and MDEV-30049.
The server may ask storage engines to unlock when the original sql
command is not UNLOCK. This patch makes sure that spider honours these
requests, so that the server has the correct idea which tables are
locked and which are not.
MDEV-29456, MDEV-29667, MDEV-30049: a later LOCK statement would, as
the first step, unlock locked tables and clear the OPTION_TABLE_LOCK
bit in thd->variables.option_bits, as well as locked_tables_list,
indicating no tables are locked. If Spider does not unlock because the
sql command is not UNLOCK, and if after this the LOCK statement fails
to lock any tables, these indications that no tables are locked
remains, so a later UNLOCK TABLES; statement would not try to unlock
any table. Causing later statements requiring mdl locks to hang on
waiting until lock_wait_timeout (default 1h) has passed.
MDEV-30014: when a LOCK statement tries to lock more than one tables,
say t2 and t3 as in mdev_30014.test, and t2 succeeds but t3 fails, the
sql layer would try to undo by unlocking t2, and again, if Spider does
not honour this request, the sql layer would assume t2 has been
unlocked, but later actions on t2 or t2's remote table could hang on
waiting for the mdl.
Spider populates its lock lists (a hash) in store_lock(), and normally
clears them in the actual lock_tables(). However, if lock_tables()
fails, there's no reset_lock() method for storage engine handlers,
which can cause bad things to happen. For example, if one of the table
involved is dropped and recreated, or simply TRUNCATEd, when executing
LOCK TABLES again, the lock lists would be queried again in
store_lock(), which could cause access to freed space associated with
the dropped table.
Spider GBH's query rewrite of table joins is overly complex and
error-prone. We replace it with something closer to what
dbug_print() (more specifically, print_join()) does, but catered to
spider.
More specifically, we replace the body of
spider_db_mbase_util::append_from_and_tables() with a call to
spider_db_mbase_util::append_join(), and remove downstream append_X
functions.
We make it handle const tables by rewriting them as (select 1). This
fixes the main issue in MDEV-26247.
We also ban semijoin from spider gbh, which fixes MDEV-31645 and
MDEV-30392, as semi-join is an "internal" join, and "semi join" does
not parse, and it is different from "join" in that it deduplicates the
right hand side
Not all queries passed to a group by handler are valid (MDEV-32273),
for example, a join on expr may refer outer fields not in the current
context. We detect this during the handler creation when walking the
join. See also gbh_outer_fields_in_join.test.
It also skips eliminated tables, which fixes MDEV-26193.
Spider gbh query rewrite should get table for fields in a simple way.
Add a method spider_fields::find_table that searches its table holders
to find table for a given field. This way we will be able to get rid
of the first pass during the gbh creation where field_chains and
field_holders are created.
We also check that the field belongs to a spider table while walking
through the query, so we could remove
all_query_fields_are_query_table_members(). However, this requires an
earlier creation of the table_holder so that tables are added before
checking. We do that, and in doing so, also decouple table_holder and
spider_fields
Remove unused methods and fields. Add comments.
Two methods from spider_fields. There are probably more of these
conn_holder related methods that can be removed
reappend_tables_part()
reappend_tables()
When spider_db_delete_all_rows() is called, the supplied spider->conns
may have already been freed. The existing mechanism has spider_trx own
the connections in trx_conn_hash and it may free a conn during the
cleanup after a query. When running a delete query and if the table is
in the table cache, ha_spider::open() would not be called which would
recreate the conn. So we recreate the conn when necessary during
delete by calling spider_check_trx_and_get_conn().
We also reduce code duplication as delete_all_rows() and truncate()
has almost identical code, and there's no need to assign
wide_handler->sql_command in these functions because it has already
been correctly assigned.
Problem:
Item_func_date_format::val_str() and make_date_time() did not take into
account that the format string and the result string
(separately or at the same time) can be of a tricky character set
like UCS2, UTF16, UTF32. As a result, DATE_FORMAT() could generate
an ill-formed result which crashed on DBUG_ASSERTs testing well-formedness
in other parts of the code.
Fix:
1. class String changes
Removing String::append_with_prefill(). It was not compatible with
tricky character sets. Also it was inconvenient to use and required
too much duplicate code on the caller side.
Adding String::append_zerofill() instead. It's compatible with tricky
character sets and is easier to use.
Adding helper methods Static_binary_string::q_append_wc() and
String::append_wc(), to append a single wide character
(a Unicode code point in my_wc_t).
2. storage/spider changes
Removing spider_string::append_with_prefill().
It used String::append_with_prefix() inside, but it was unused itself.
3. Changing tricky charset incompatible code pieces in make_date_time()
to compatible replacements:
- Fixing the loop scanning the format string to iterate in terms
of Unicode code points (using mb_wc()) rather than in terms
of "char" items.
- Using append_wc(my_wc_t) instead of append(char) to append
a single character to the result string.
- Using append_zerofill() instead of append_with_prefill() to
append date/time numeric components to the result string.
Spider is part of the server, and there's no need to check the
version.
All spider plugins are uninstalled in clean_up_spider.inc
DROP SERVER IF EXISTS makes things easier
Removed some redundant hint related string literals from
spd_db_conn.cc
Clean up SPIDER_PARAM_*_[CHAR]LEN[S]
Adding tests covering monitoring_kind=2. What it does is that it reads
from mysql.spider_link_mon_servers with matching db_name, table_name,
link_id, and does not do anything about that...
How monitoring_* can be useful: in the deprecated spider high
availability feature, when one remote fails, spider will try another
remote, which apparently makes use of these table parameters.
A test covering the query_cache_sync table param. Some further tests
on some spider table params.
Wrapper should be case insensitive.
Code documentation on spider priority binary tree.
Add an assertion that static_key_cardinality is always -1. All tests
pass still
This helps eliminate "server exists" failures
Also, spider/bugfix.mdev_29676, when enabled after MDEV-29525 is
pushed will fail because we have not --recorded the result. But the
failure will only emerge when working on MDEV-31138 where we manually
re-enable this test, so let's worry about that then.
The direct aggregate mechanism sems to be only intended to work when
otherwise a full table scan query will be executed from the spider
node and the aggregation done at the spider node too. Typically this
happens in sub_select(). In the test spider.direct_aggregate_part
direct aggregate allows to send COUNT statements directly to the data
nodes and adds up the results at the spider node, instead of iterating
over the rows one by one at the spider node.
By contrast, the group by handler (GBH) typically sends aggregated
queries directly to data nodes, in which case DA does not improve the
situation here.
That is why we should fix it by disabling DA when GBH is used.
There are other reasons supporting this change. First, the creation of
GBH results in a call to change_to_use_tmp_fields() (as opposed to
setup_copy_fields()) which causes the spider DA function
spider_db_fetch_for_item_sum_funcs() to work on wrong items. Second,
the spider DA function only calls direct_add() on the items, and the
follow-up add() needs to be called by the sql layer code. In
do_select(), after executing the query with the GBH, it seems that the
required add() would not necessarily be called.
Disabling DA when GBH is used does fix the bug. There are a few
other things included in this commit to improve the situation with
spider DA:
1. Add a session variable that allows user to disable DA completely,
this will help as a temporary measure if/when further bugs with DA
emerge.
2. Move the increment of direct_aggregate_count to the spider DA
function. Currently this is done in rather bizarre and random
locations.
3. Fix the spider_db_mbase_row creation so that the last of its row
field (sentinel) is NULL. The code is already doing a null check, but
somehow the sentinel field is on an invalid address, causing the
segfaults. With a correct implementation of the row creation, we can
avoid such segfaults.
Spider connection string is a comma-separated parameter definitions,
where each definition is of the form "<param_title> <param_value>",
where <param_value> is quote delimited on both ends, with backslashes
acting as an escaping prefix.
Despite the simple syntax, the existing spider connection string
parser was poorly-written, complex, hard to reason and error-prone,
causing issues like the one described in MDEV-31117. For example it
treated param title the same way as param value when assigning, and
have nonsensical fields like delim_title_len and delim_title.
Thus as part of the bugfix, we clean up the spider comment connection
string parsing, including:
- Factoring out some code from the parsing function
- Simplify the struct `st_spider_param_string_parse`
- And any necessary changes caused by the above changes
This patch adds for "--ps-protocol" second execution
of queries "SELECT".
Also in this patch it is added ability to disable/enable
(--disable_ps2_protocol/--enable_ps2_protocol) second
execution for "--ps-prototocol" in testcases.
The existing (incorrect) overriding mechanism is:
Non-minus-one var value overrides table param overrides default value.
Before MDEV-27169, unspecified var value is -1. So if the user sets
both the var to be a value other than -1 and the table param, the var
value will prevail, which is incorrect.
After MDEV-27169, unspecified var value is default value. So if the
user does not set the var but sets the table param, the default value
will prevail, which is even more incorrect.
This patch fixes it so that table param, if specified, always
overrides var value, and the latter if not specified or set to -1,
falls back to the default value
We achieve this by replacing all such overriding in spd_param.cc with
macros that override in the correct way, and removing all the
"overriding -1" lines involving table params in
spider_set_connect_info_default() except for those table params not
defined as sysvar/thdvar in spd_params.cc
We also introduced macros for non-overriding sysvar and thdvar, so
that the code is cleaner and less error-prone
In server versions where MDEV-27169 has not been applied, we also
backport the patch, that is, replacing -1 default values with real
default values
In server versions where MDEV-28006 has not been applied, we do the
same for udf params
This fixes mdev_26541.test, and the new clean_up_spider.inc will be
useful for other tests where part of deinit_spider does not apply,
e.g. those testing spider initialisation only.
