Develop Reference

Redisson client ; RedisTimeoutException issue

I am using Google cloud managed redis cluster(v5) via redisson(3.12.5)
Following are my SingleServer configurations in yaml file
singleServerConfig:
idleConnectionTimeout: 10000
connectTimeout: 10000
timeout: 3000
retryAttempts: 3
retryInterval: 1500
password: null
subscriptionsPerConnection: 5
clientName: null
address: "redis://127.0.0.1:6379"
subscriptionConnectionMinimumIdleSize: 1
subscriptionConnectionPoolSize: 50
connectionMinimumIdleSize: 40
connectionPoolSize: 250
database: 0
dnsMonitoringInterval: 5000
threads: 0
nettyThreads: 0
codec: !<org.redisson.codec.JsonJacksonCodec> {}
I am getting following exceptions when I increase the load on my application
org.redisson.client.RedisTimeoutException: Unable to acquire connection! Increase connection pool size and/or retryInterval settings Node source: NodeSource
org.redisson.client.RedisTimeoutException: Command still hasn't been written into connection! Increase nettyThreads and/or retryInterval settings. Payload size in bytes: 34. Node source: NodeSource
It seems there is no issue on redis cluster and i think i need to make tweaking in my client side redis connection pooling confs(mentioned above) to make it work.
Please suggest me the changes i need to make in my confs
I am also curious if I should close the Redis connection after making get/set calls. I have tried finding this but found nothing conclusive on how to close Redis connections
One last thing that I want to ask is that is there any mechanism to get Redis connection pool stats(active connection, idle connection etc ) in Redisson
Edit1:
I have tried by changing values following values in 3 different iterations
Iteration 1:
idleConnectionTimeout: 30000
connectTimeout: 30000
timeout: 30000
Iteration 2:
nettyThreads: 0
Iteration 3:
connectionMinimumIdleSize: 100
connectionPoolSize: 750
I have tried these things but nothing has worked for me
Any help is appreciated.
Thanks in advance

Assuming you are getting low memory alerts on your cache JVM.
You may have to analyze the traffic and determine 2 things
Too many parallel cache persists.
Huge chunk of data being persisted.
Both can be determined by the traffic on your server.
For option 1 configuring pool-size would solve you issue, but for option 2 you may have to refactor your code to persist data in smaller chunks.

Try to set nettyThreads = 64 settings

SQL Warning with Spring boot and Sybase

I am getting a lot of SQL Warning in the logs with the spring boot and sybase.
o.h.engine.jdbc.spi.SqlExceptionHelper : [] SQL Warning Code: 0, SQLState: 010SK
o.h.engine.jdbc.spi.SqlExceptionHelper : [] 010SK: Database cannot set connection option SET_READONLY_TRUE.
o.h.engine.jdbc.spi.SqlExceptionHelper : [] 010SK: Database cannot set connection option SET_READONLY_FALSE.
Could anyone explain the reason behind this?

Solution 1:
java.sql.Connection has a setReadOnly(boolean) method that is meant to notify the database of the type of result set being requested in order to perform any optimizations. However Sybase ASE doesn't require any optimizations, therefore setReadOnly() produces a SQLWarning.
In order to suppress the message you'll need to update the spt_mda table in the MASTER database.
update spt_mda set querytype = 4, set query = '0'
where mdinfo = 'SET_READONLY_FALSE'
and
update spt_mda set querytype = 4, set query = '0'
where mdinfo = 'SET_READONLY_TRUE'
These two entries (they are the only ones) are set to a querytype of 3 by default, which means "not supported", which explains the SQLWarning.
Changing them to a 4 (meaning boolean values) with a query type of "0" basically causes the JDBC Driver to return false without the warning..
Solution 2:
You might turn off/on on logging for specific part of hibernate logging modules, these are different configurations:
# Hibernate logging
# Log everything (a lot of information, but very useful for troubleshooting)
log4j.logger.org.hibernate=FATAL
# Log all SQL DML statements as they are executed
log4j.logger.org.hibernate.SQL=INHERITED
# Log all JDBC parameters
log4j.logger.org.hibernate.type=INHERITED
# Log all SQL DDL statements as they are executed
log4j.logger.org.hibernate.tool.hbm2ddl=INHERITED
# Log the state of all entities (max 20 entities) associated with the session at flush time
log4j.logger.org.hibernate.pretty=INHERITED
# Log all second-level cache activity
log4j.logger.org.hibernate.cache=INHERITED
# Log all OSCache activity - used by Hibernate
log4j.logger.com.opensymphony.oscache=INHERITED
# Log transaction related activity
log4j.logger.org.hibernate.transaction=INHERITED
# Log all JDBC resource acquisition
log4j.logger.org.hibernate.jdbc=INHERITED
# Log all JAAS authorization requests
log4j.logger.org.hibernate.secure=INHERITED
Possible values:
OFF
FATAL
ERROR
WARN
INFO
DEBUG
TRACE
ALL

jooq insert throws an exception when another thread is reading from same table

I have a table where I am inserting records using record.insert() method. I believe this method is doing an insert and then a select but in a different transactions. At the same time I have another thread which pools this table for records processes them and then deletes them.
In some cases I am getting the below exception:
org.jooq.exception.NoDataFoundException: Exactly one row expected for refresh. Record does not exist in database.
at org.jooq.impl.UpdatableRecordImpl.refresh(UpdatableRecordImpl.java:345)
at org.jooq.impl.TableRecordImpl.getReturningIfNeeded(TableRecordImpl.java:232)
at org.jooq.impl.TableRecordImpl.storeInsert0(TableRecordImpl.java:208)
at org.jooq.impl.TableRecordImpl$1.operate(TableRecordImpl.java:169)
My solution was to use DSL.using(configuration()).insertInto instead of record.insert().
My question is shouldn't the insert and fetch be done in the same transaction?
UPDATE:
This is a dropwizard app that is using jooqbundle: com.bendb.dropwizard:dropwizard-jooq.
The configuration is injected in the DAO, the insert is as follows:
R object = // jooq record
object.attach(configuration);
object.insert();
On the second thread I am just selecting some records from this table, processing them and then deleting them
Jooq logs clearly shows that the 2 queries are not run in same transaction:
14:07:09.550 [main] DEBUG org.jooq.tools.LoggerListener - -> with bind values : insert into "queue"
....
14:07:09.083', 1)
14:07:09.589 [main] DEBUG org.jooq.tools.LoggerListener - Affected row(s) : 1
14:07:09.590 [main] DEBUG org.jooq.tools.StopWatch - Query executed : Total: 47.603ms
14:07:09.591 [main] DEBUG org.jooq.tools.StopWatch - Finishing : Total: 48.827ms, +1.223ms
14:07:09.632 [main] DEBUG org.jooq.tools.LoggerListener - Executing query : select "queue"."
I do not see the "autocommit off" or "savepoint" statements in the logs which are generally printed by jooq in case the queries are run in a transaction. I hope this helps, let me know if you need more info
UPDATE 2:
Jooq version is 3.9.1
mysql version 5.6.23
Database and jooq entry yml file:
database:
driverClass: com.mysql.jdbc.Driver
user: ***
password: ***
url: jdbc:mysql://localhost:3306/mySchema
properties:
charSet: UTF-8
characterEncoding: UTF-8
# the maximum amount of time to wait on an empty pool before throwing an exception
maxWaitForConnection: 1s
# the SQL query to run when validating a connection's liveness
validationQuery: "SELECT 1"
# the timeout before a connection validation queries fail
validationQueryTimeout: 3s
# initial number of connections
initialSize: 25
# the minimum number of connections to keep open
minSize: 25
# the maximum number of connections to keep open
maxSize: 25
# whether or not idle connections should be validated
checkConnectionWhileIdle: true
# the amount of time to sleep between runs of the idle connection validation, abandoned cleaner and idle pool resizing
evictionInterval: 10s
# the minimum amount of time an connection must sit idle in the pool before it is eligible for eviction
minIdleTime: 1 minute
jooq:
# The flavor of SQL to generate. If not specified, it will be inferred from the JDBC connection URL. (default: null)
dialect: MYSQL
# Whether to write generated SQL to a logger before execution. (default: no)
logExecutedSql: no
# Whether to include schema names in generated SQL. (default: yes)
renderSchema: yes
# How names should be rendered in generated SQL. One of QUOTED, AS_IS, LOWER, or UPPER. (default: QUOTED)
renderNameStyle: QUOTED
# How keywords should be rendered in generated SQL. One of LOWER, UPPER. (default: UPPER)
renderKeywordStyle: UPPER
# Whether generated SQL should be pretty-printed. (default: no)
renderFormatted: no
# How parameters should be represented. One of INDEXED, NAMED, or INLINE. (default: INDEXED)
paramType: INDEXED
# How statements should be generated; one of PREPARED_STATEMENT or STATIC_STATEMENT. (default: PREPARED_STATEMENT)
statementType: PREPARED_STATEMENT
# Whether internal jOOQ logging should be enabled. (default: no)
executeLogging: no
# Whether optimistic locking should be enabled. (default: no)
executeWithOptimisticLocking: yes
# Whether returned records should be 'attached' to the jOOQ context. (default: yes)
attachRecords: yes
# Whether primary-key fields should be updatable. (default: no)
updatablePrimaryKeys: no
Have included the jooq bundle in the Application class as described in https://github.com/benjamin-bader/droptools/tree/master/dropwizard-jooq.
Using https://github.com/xvik/dropwizard-guicey to inject the configuration into each DAO.
The guide module has the following binding:
bind(Configuration.class).toInstance(jooqBundle.getConfiguration());

Apache Solr - waiting on sql queries when delta-import command is executed

I'm using PostgreSQL 8.2.9, Solr 3.1, Tomcat 5.5
I have following problem:
When I execute delta-import - /dataimport?command=delta-import - any update queries to database are not responding for about 30 seconds.
I can easily repeat this behaviour (using psql or hibernate):
PSQL:
Execute delta-import
Immediately in psql - run SQL query: 'UPDATE table SET ... WHERE id = 1;' several times
The second/third/... time - I must wait ~30 seconds for query to return
Hibernate:
In logs - hibernate waits ~30 seconds on method 'doExecuteBatch(...)' after setting query parameters
No other queries are executed when I'm testing this. On the other hand when I'm executing other commands (like full-import, etc.)- everything works perfectly fine.
In Solr's dataconfig.xml:
I have readOnly attribute set to true on PostgreSQL dataSource.
deltaImportQuery, deltaQuery, ... on entity tags don't lock database (simple SELECT's)
Web app (using hibernate) logs:
2012-01-08 18:54:52,403 DEBUG my.package.Class1... Executing method: save
2012-01-08 18:55:26,707 DEBUG my.package.Class1... Executing method: list
Solr logs:
INFO: [] webapp=/search path=/dataimport params={debug=query&command=delta-import&commit=true} status=0 QTime=1
2012-01-08 18:54:50 org.apache.solr.handler.dataimport.DataImporter doDeltaImport
INFO: Starting Delta Import
...
2012-01-08 18:54:50 org.apache.solr.handler.dataimport.JdbcDataSource$1 call
INFO: Time taken for getConnection(): 4
...
FINE: Executing SQL: select ... where last_edit_date > '2012-01-08 18:51:43'
2012-01-08 18:54:50 org.apache.solr.core.Config getNode
...
FINEST: Time taken for sql :4
...
INFO: Import completed successfully
2012-01-08 18:54:50 org.apache.solr.update.DirectUpdateHandler2 commit
INFO: start commit(optimize=true,waitFlush=false,waitSearcher=true,expungeDeletes=false)
2012-01-08 18:54:53 org.apache.solr.core.Config getNode
...
2012-01-08 18:54:53 org.apache.solr.update.DirectUpdateHandler2 commit
INFO: end_commit_flush
...
2012-01-08 18:54:53 org.apache.solr.handler.dataimport.DocBuilder execute
INFO: Time taken = 0:0:2.985
There're no 'SELECT ... FOR UPDATE / LOCK / etc.' queries in above logs.
I have set logging for PostgreSQL - there're no locks. Even sessions are set to:
Jan 11 14:33:07 test postgres[26201]: [3-1] <26201> LOG: execute <unnamed>: SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY
Jan 11 14:33:07 test postgres[26201]: [4-1] <26201> LOG: execute <unnamed>: SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL READ UNCOMMITTED
Why is this happening? This looks like some kind of database lock but then why when import is completed (2 secs) queries are still waiting (for 30 secs)?

The Update waiting for the SELECT statement to complete before executing. Not a lot you can do about that that I'm aware of. We get around the issue by doing our indexing in batches. Multiple SELECT statements are fine, but UPDATE and DELETE affect the records and wont execute until it can lock the table.

Ok. It was hard to find solution to this problem.
The reason was the underlying platform - disk write saturation. There was too many small "disk-write"'s that consumed all disk-write power.
Now we have new agreement with our service layer provider.
Test query:
while true ; do echo "UPDATE table_name SET type='P' WHERE type='P'" | psql -U user -d database_name ; sleep 1 ; done
plus making changes via out other application, plus update index simultaneously.
This was before platform change:
And here is how it works now:

Hibernate + enabling SQLite Pragmas to gain speed on Windows 7 machine

Used software:
hibernate 3.6
sqlite jbdc 3.6.0
java jre 1.6.X
I have a problem with transferring data over a tcp connection ( 20 000 entrys )
create a sqlite database with the help of hibernate
use hibernateview and hibernate annotations to create querys
hibernate proberties are also used
storing 20 000 entries with hibernate and NO sqlite pragmas enabled lasts nearly 6 minutes ( ~ 330 sec) on Windows 7
storing 20 000 entries without hibernate and all relevant sql pragmas enabled lasts ca 2 minutes ( ~ 109 sec ) on windows 7
tests with hibernate and sqlite without pragmas on windows XP and windows Vista run fast, but on win7 it lasts nearly
3 times ( ~ 330 sec - win 7) as long as on the XP machine
on windows 7 we want to activate sqlite pragmas to gain speed boost
relevant pragmas are:
PRAGMA cache_size = 400000;
PRAGMA synchronous = OFF;
PRAGMA count_changes = OFF;
PRAGMA temp_store = MEMORY;
PRAGMA auto_vacuum = NONE;
Problem: we must use hibernate ( no Nhibernate ! )
Questions:
how to enable these pragmas in hibernate sqlite connection if its possible?
Is it possible to do so with using hibernate?

I was also looking for some way to set another pragma: PRAGMA foreign_keys = ON for hibernate connections. I didn't find anything on the subject and the only solution I came up with is to decor SQLite JDBC driver and set required pragma each time new connection is retrieved. See sample code below:
#Override
public Connection connect(String url, Properties info) throws SQLException {
final Connection connection = originalDriver.connect(url, info);
initPragmas(connection);
return connection;
}
private void initPragmas(Connection connection) throws SQLException {
//Enabling foreign keys
connection.prepareStatement("PRAGMA foreign_keys = ON;").execute();
}
Full sample is here: https://gist.github.com/52dbc7066787684de634. Then when initializing hibernate.connection.driver_class property just set it to your package.DriverDecorator

Inserts one-by-one can be very slow; you may want to consider batching. Please see my answer to this other post.

for PRAGMA foreign_keys = ON equivalent
hibernate.connection.foreign_keys=true
or
<property name="connection.foreign_keys">true</property>
depending on your strategy