ignite query cache with value as list of objects - ignite

I am using ignite cache with key as String and value as Collection of objects (similar type) say List.
Now i would like to query on the students stored in cache let's say 5 top scored students.
defined the configuration as below
CacheConfiguration<String, List<Student>> cfg = new CacheConfiguration<String, List<Student>>("students");
ignite = Ignition.start("/usr/localc/ignite/examples/config/example-ignite.xml");
cfg.setIndexedTypes(String.class, List.class);
Now I fired a query like
SqlFieldsQuery qry = new SqlFieldsQuery("select count(*) from Person");
Then got exception like
Exception in thread "main" java.lang.AbstractMethodError: org.apache.ignite.internal.processors.query.h2.opt.GridH2Table$ScanIndex.getCost(Lorg/h2/engine/Session;[I[Lorg/h2/table/TableFilter;ILorg/h2/result/SortOrder;Ljava/util/HashSet;)D
at org.h2.table.TableFilter.getBestPlanItem(TableFilter.java:203)
at org.h2.table.Plan.calculateCost(Plan.java:123)
at org.h2.command.dml.Optimizer.testPlan(Optimizer.java:183)
at org.h2.command.dml.Optimizer.calculateBestPlan(Optimizer.java:79)
at org.h2.command.dml.Optimizer.optimize(Optimizer.java:242)
at org.h2.command.dml.Select.preparePlan(Select.java:1014)
at org.h2.command.dml.Select.prepare(Select.java:878)
at org.h2.command.Parser.prepareCommand(Parser.java:259)
at org.h2.engine.Session.prepareLocal(Session.java:560)
at org.h2.engine.Session.prepareCommand(Session.java:501)
at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1202)
at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:73)
at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:290)
at org.apache.ignite.internal.processors.query.h2.IgniteH2Indexing.prepareStatement(IgniteH2Indexing.java:406)
at org.apache.ignite.internal.processors.query.h2.IgniteH2Indexing.queryTwoStep(IgniteH2Indexing.java:1121)
at org.apache.ignite.internal.processors.query.GridQueryProcessor$2.applyx(GridQueryProcessor.java:732)
at org.apache.ignite.internal.processors.query.GridQueryProcessor$2.applyx(GridQueryProcessor.java:730)
at org.apache.ignite.internal.util.lang.IgniteOutClosureX.apply(IgniteOutClosureX.java:36)
at org.apache.ignite.internal.processors.query.GridQueryProcessor.executeQuery(GridQueryProcessor.java:1666)
at org.apache.ignite.internal.processors.query.GridQueryProcessor.queryTwoStep(GridQueryProcessor.java:730)
at org.apache.ignite.internal.processors.cache.IgniteCacheProxy.query(IgniteCacheProxy.java:700)
at com.tcs.enm.processor.Main.main(Main.java:47)
Can any one help me how to query ???

To execute such query you should store each Student as a separate entry. Student class should have all the annotations defining fields and indexes and the cache configuration should look like this:
cfg.setIndexedTypes(String.class, Student.class);
For more details refer to this documentation: https://apacheignite.readme.io/docs/sql-queries

For anyone in the future who has this issue, this error message is likely due to using an incorrect version of H2.
http://apache-ignite-users.70518.x6.nabble.com/Exception-while-trying-to-access-cache-via-JDBC-API-td8648.html#a8651
If you're using Ignite 1.7, you need h2database 1.4.191.
Note that h2database 1.4.192 WILL give you the exception in the question because there are some changes in 192 which Ignite wasn't made to handle
I went through my packages and changed the H2 version to 1.4.191 and it fixed my problems.

Related

Spark - Failed to load collect frame - "RetryingBlockFetcher - Exception while beginning fetch"

We have a Scala Spark application, that reads something like 70K records from the DB to a data frame, each record has 2 fields.
After reading the data from the DB, we make minor mapping and load this as a broadcast for later usage.
Now, in local environment, there is an exception, timeout from the RetryingBlockFetcher while running the following code:
dataframe.select("id", "mapping_id")
.rdd.map(row => row.getString(0) -> row.getLong(1))
.collectAsMap().toMap
The exception is:
2022-06-06 10:08:13.077 task-result-getter-2 ERROR
org.apache.spark.network.shuffle.RetryingBlockFetcher Exception while
beginning fetch of 1 outstanding blocks
java.io.IOException: Failed to connect to /1.1.1.1:62788
at
org.apache.spark.network.client.
TransportClientFactory.createClient(Transpor .tClientFactory.java:253)
at
org.apache.spark.network.client.
TransportClientFactory.createClient(TransportClientFactory.java:195)
at
org.apache.spark.network.netty.
NettyBlockTransferService$$anon$2.
createAndStart(NettyBlockTransferService.scala:122)
In the local environment, I simply create the spark session with local "spark.master"
When I limit the max of records to 20K, it works well.
Can you please help? maybe I need to configure something in my local environment in order that the original code will work properly?
Update:
I tried to change a lot of Spark-related configurations in my local environment, both memory, a number of executors, timeout-related settings, and more, but nothing helped! I just got the timeout after more time...
I realized that the data frame that I'm reading from the DB has 1 partition of 62K records, while trying to repartition with 2 or more partitions the process worked correctly and I managed to map and collect as needed.
Any idea why this solves the issue? Is there a configuration in the spark that can solve this instead of repartition?
Thanks!

Apache Ignite sql query returns only cache contents, not complete results from database

My Ignite nodes (2 server nodes - let's call them A and B) are configured as follows:
ccfg.setCacheMode(CacheMode.PARTITIONED);
ccfg.setAtomicityMode(CacheMode.TRANSACTIONAL);
ccfg.setReadThrough(true);
ccfg.setWriteThrough(true);
ccfg.setWriteBehindEnabled(true);
ccfg.setWriteBehindBatchSize(10000);
Node A is started first, from command line as follows:
apache-ignite-fabric-2.2.0-bin>bin/ignite.bat config/default-config.xml
Node B is started from java code by running
public static void main(String[] args) throws Exception {
Ignite ignite = Ignition.start(ServerConfigurationFactory.createConfiguration());
ignite.cache("MyCache").loadCache(null);
...
}
(jar containing ServerConfigurationFactory is put in the apache-ignite-fabric-2.2.0-bin\libs directory so Node A and B are on the same cluster..otherwise there is an error)
I have a query that is supposed to return 9061 results from the database. After the cache loading process in Node B, I went to the Web Console and ran a simple count SQL statement against the caches. There is a button "Execute on selected node" that allows you to choose a specific cache to query. I queried Node A and got a count of 2341, and on Node B I get a count of 2064. If I just use the "Execute" button I get 4405 which is just the total of node A and B. Obviously they are missing 4656 records (9061 total records in db - 4405 in nodes A and B). I also ran the same count query in Java code using SqlFieldsQuery and I also get 4405.
Since readThrough is set to true I expected Ignite to also return results that are not in memory. But this is not the case because it just returns whatever is on the cache. Am I doing something wrong here? Thank you.
Read though works only for key-value APIs, so SQL engine assumes that all required data is preloaded from database prior to running a query.
If your data set doesn't fit in memory and you can't preload all the data, you can use native Ignite persistence storage: https://apacheignite.readme.io/docs/distributed-persistent-store

Invalid operation result set is closed errorcode 4470 sqlstate null - DB2 data extract

I am running a very simple query and trying to extract the results to a text file. The entire query is essentially what is below, I am selecting everything from one single table with one piece of where criteria which is limiting the data to one month's worth. After it has extracted around 1.2 gig this error shows up. Is there any way that I can work around this other than extracting smaller date ranges? I am trying to pull a couple of years worth of data so if I can only get it a few days at a time it will take a lot of manual work.
I am currently using the free trial of a DB2 query tool - Razor SQL if that makes a difference, I can probably purchase different software if it would help. I am trying to get IBM's tool but for some reason it freezes during the download so I am still working on that. I have searched about this error but everything I see seems much more complex than what I am doing and I can't tell if it applies or not. Thanks in advance.
select *
from MyTable
where date_col between date '2014-01-01' and date '2014-01-31'
I stumbled at this error too, found out it is related to db2jcc.jar (type 4) driver.
Excerpt: If there are no items in the result set left (or to begin with), the Result set is closed automatically and therefore the Exception. Suggestion is to handle it in the application, perhaps in my case, I started checking if(rs.next()) but otherwise, there is a work around. Check out the source link below for how you can set some properties to Data source and avoid exception.
Source :
"Invalid operation: result set is closed" error with Data Server Driver for JDBC
In my case, i missed some properties in WAS, after add allowNextOnExhaustedResultSet the issue is fixed.
1.Log in to the WebSphere Application Server administration console.
2.Select Resources > JDBC > Data sources > Application Center DataSource name > Custom properties and click New.
3.In the Name field, enter allowNextOnExhaustedResultSet.
4.In the Value field, type 1.
5.Change the type to java.lang.Integer.
6.Click OK.
Sometimes you need also check whether resultSetHoldability properties exists. Details refer to here.
I encountered this failure also when ugrading from JDBC Type 2 driver (db2java.zip) JDBC type 4 driver (db2jcc4.jar)
Statement statement = results.getStatement();
if (statement != null)
{
connection = statement.getConnection(); // ** failed here
statement.close();
}
Solution was to check if the statement is closed or not as follows.
Changed to:
Statement statement = results.getStatement();
if (statement != null && !statement.isClosed()) {
{
connection = statement.getConnection();
statement.close();
}
Creating property bellow with type Integer it's worked for me:
allowNextOnExhaustedResultSet:
I had the same issue on WAS 7 so i had to add and change few this on Admin Console.
This TeamWorksRuntimeException exception should be fixed by applying APAR JR50863 which is available on top of BPM V8.5.5 or included on BPM V8.5 refresh pack 6.
For the case that the APAR does not solve the problem, try following workaround:
Log in to the WebSphere Application Server admin console
Select Resources > JDBC > Data sources > DataSource name (TeamWorksDB) > Custom properties and click New
In the Name field, enter downgradeHoldCursorsUnderXa
In the Value field, type true
Change the type to java.lang.Boolean
Click OK to save your changes
Select custom property resultSetHoldability
In the Value field, type 1
Click OK to save your changes
Source of the Answer : https://developer.ibm.com/answers/questions/194821/invalid-operation-result-set-is-closed-errorcode-4/
Restarting the app may fix the problem if connection pool lost session to Db2. If using Tomcat then connection pool property of 'testonBorrow' may reestablish the connection to Db2.

updateblob fails in Powerbuilder

In Powerbuilder I am trying to update a table (Oracle) with blob but get sqlerror, "Database statement must refer to blob variable". My declaration and updateblob statements are as follows:
blob lblob_newxml
long llong_subid
UPDATEBLOB RP_XML_FORMS SET XML_DOC = :lblob_newxml
WHERE SUBMISSION_ID = :llong_subid
USING SQLCA;
Does anybody know why it is happening and or how to solve this problem? Thanks.
To get more information on this problem and the possible causes, I'd run with one of the database traces turned on. (You can check out database trace options in the Connecting to Your Database manual; link may not be appropriate for your PB version, which you haven't mentioned yet.) This may or may not tell you more, but it tracks everything between the app and when the PB drivers pass the commands "over the wall" to the database's driver.
Good luck,
Terry.
"The PowerBuilder VM can get the SQL syntax for the following types of errors, and passes it to the Transaction object’s DBError event for the following types of errors: ..." (see this page).
If your lblob_newxml is null then use this update statement instead:
UPDATE RP_XML_FORMS SET XML_DOC = NULL
WHERE SUBMISSION_ID = :llong_subid
USING SQLCA;

Data is not properly stored to hsqldb when using pooled data source by dbcp

I'm using hsqldb to create cached tables and indexed tables.
The data being stored has pretty high frequency so I need to use a connection pool.
Also because there is a lot of data I do not call checkpoint on every commit, but rather expect the data to be flushed after 50,000 rows are inserted.
So the thing is that I can see the .data file is growing but when I connect with hsqldb client I don't see the tables and the data.
So I had 2 simple tests, one inserted single row and one inserted 60,000 rows to new table. In both cases I couldn't see the result in any hsqldb client.
(Note that I use shutdown=true)
So when I add checkpoint after each commit, it solve the problem.
Also if specify in the connection string to use log, it solves the problem (I don't want the log in production though). Also not using pooled connection solved the problem and last is using pooled data source and explicitly close it before shutdown.
So I guess that some connections in the connection pool are not being closed, preventing from the db to somehow commit the changes and make them available for the client. But then, why couldn't I see the result even with 60,000 rows?
I also would expect the pool to be closed automatically...
What am I doing wrong? What is happening behind the scene?
The code to get the data source looks like this:
Class.forName("org.hsqldb.jdbcDriver");
String url = "jdbc:hsqldb:" + m_dbRoot + dbName + "/db" + ";hsqldb.log_data=false;shutdown=true;hsqldb.nio_data_file=false";
ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(url, user, password);
GenericObjectPool connectionPool = new GenericObjectPool();
KeyedObjectPoolFactory stmtPool = new GenericKeyedObjectPoolFactory(null);
new PoolableConnectionFactory(connectionFactory, connectionPool, stmtPool, null, false, true);
DataSource ds = new PoolingDataSource(connectionPool);
And I'm using this Pooled data source to create table:
Connection c = m_dataSource.getConnection();
Statement st = c.createStatement();
String script = String.format("CREATE CACHED TABLE IF NOT EXISTS %s (id %s NOT NULL, entity %s NOT NULL, PRIMARY KEY (id));", m_tableName, m_idGenerator.getIdType(), TABLE_ENTITY_TYPE);
st.execute(script);
c.close;
st.close();
And insert rows:
Connection c = m_dataSource.getConnection();
c.setAutoCommit(false);
Statement stmt = c.prepareStatement(m_sqlInsert);
stmt.setObject(1, id);
stmt.setBinaryStream(2, Serializer.Helper.serialize(m_serializer, entity));
stmt.executeUpdate();
stmt.close();
stmt = null;
c.commit();
c.close();
stmt.close();
so the above seems to add data but it cannot be seen.
When I explicitly called
connectionPool.close();
Then and only then I could see the result.
I also tried to use JDBCDataSource and it worked as well.
So what is going on? And what is the right way to do this?
Your method of accessing the database from outside your application process is simply wrong.
Only one java process is supposed to connect to the file: database.
In order to achieve your aim, launch an HSQLDB server within your application, using exactly the same JDBC URL. Then connect to this server from the external client.
See the Guide:
http://www.hsqldb.org/doc/2.0/guide/listeners-chapt.html#lsc_app_start
Update: The OP commented that the external client was used after the application had stopped. Because you have turned the log off with hsqldb.log_data=false, nothing is persisted permanently. You need to perform an explicit CHECKPOINT or SHUTDOWN when your application completes its work. You cannot rely on shutdown=true at all, even without connection pooling.
See the Guide:
http://www.hsqldb.org/doc/2.0/guide/deployment-chapt.html#dec_bulk_operations