Spring Data Solr #Transaction Commits - spring

Question

I currently have a setup where data is inserted into a database, as well as indexed into Solr. These two steps are wrapped in a spring-managed transaction via the #Transaction annotation. What I've noticed is that spring-data-solr issues an update with the following parameters whenever the transaction is closed : params{commit=true&softCommit=false&waitSearcher=true}
#Transactional
public void save(Object toSave){
dbRepository.save(toSave);
solrRepository.save(toSave);
}
The rate of commits into solr is fairly high, so ideally I'd like send data to the solr index, and have solr auto commit at regular intervals. I have the autoCommit (and autoSoftCommit) set in my solrconfig.xml, but since spring-data-solr is sending those commit parameters, it does a hard commit every time.
I'm aware that I can drop down to the SolrTemplate API and issue commits manually, I would like to keep the solr repository.save call within a spring-managed transaction if possible. Is there a way to modify the parameters that are sent to solr on commit?

Answer 1

After putting in an IDE debug breakpoint in org.springframework.data.solr.repository.support.SimpleSolrRepository here:
private void commitIfTransactionSynchronisationIsInactive() {
if (!TransactionSynchronizationManager.isSynchronizationActive()) {
this.solrOperations.commit(solrCollectionName);
}
}
I discovered that wrapping my code as #Transactional (and other details to actually enable the framework to begin/end code as a transaction) doesn't achieve what we expect with "Spring Data for Apache Solr". The stacktrace shows the Proxy and Transaction Interceptor classes for our code's Transactional scope but then it also shows the framework starting its own nested transaction with another Proxy and Transaction Interceptor of its own. When the framework exits its CrudRepository.save() method my code calls, the action to commit to Solr is done by the framework's nested transaction. It happens before our outer transaction is exited. So, the attempt to batch-process many saves with one commit at the end instead of one commit for every save is futile. It seems, for this area in my code, I'll have to make use of SolrJ to save (update) my entities to Solr and then have "my" transaction's exit be followed with a commit.

Answer 2

If using Spring Solr, I found using the SolrTemplate bean allows you to 'batch' updates when adding data to the Solr index. By using the bean for SolrTemplate, you can use "addBeans" method, which will add a collection to the index and not commit until the end of the transaction. In my case, I started out using solrClient.add() and taking up to 4 hours for my collection to get saved to the index by iterating over it, as it commits after every single save. By using solrTemplate.addBeans(Collect<?>), it finishes in just over 1 second, as the commit is on the entire collection. Here is a code snippet:
#Resource
SolrTemplate solrTemplate;
public void doReindexing(List<Image> images) {
if (images != null) {
/* CMSSolrImage is a class with #SolrDocument mappings.
* the List<Image> images is a collection pulled from my database
* I want indexed in Solr.
*/
List<CMSSolrImage> sImages = new ArrayList<CMSSolrImage>();
for (Image image : images) {
CMSSolrImage sImage = new CMSSolrImage(image);
sImages.add(sImage);
}
solrTemplate.saveBeans(sImages);
}
}

Answer 3

The way I've done something similar is to create a custom repository implementation of the save methods.
Interface for the repository:
public interface FooRepository extends SolrCrudRepository<Foo, String>, FooRepositoryCustom {
}
Interface for the custom overrides:
public interface FooRepositoryCustom {
public Foo save(Foo entity);
public Iterable<Foo> save(Iterable<Foo> entities);
}
Implementation of the custom overrides:
public class FooRepositoryImpl {
private SolrOperations solrOperations;
public SolrSampleRepositoryImpl(SolrOperations fooSolrOperations) {
this.solrOperations = fooSolrOperations;
}
#Override
public Foo save(Foo entity) {
Assert.notNull(entity, "Cannot save 'null' entity.");
registerTransactionSynchronisationIfSynchronisationActive();
this.solrOperations.saveBean(entity, 1000);
commitIfTransactionSynchronisationIsInactive();
return entity;
}
#Override
public Iterable<Foo> save(Iterable<Foo> entities) {
Assert.notNull(entities, "Cannot insert 'null' as a List.");
if (!(entities instanceof Collection<?>)) {
throw new InvalidDataAccessApiUsageException("Entities have to be inside a collection");
}
registerTransactionSynchronisationIfSynchronisationActive();
this.solrOperations.saveBeans((Collection<? extends T>) entities, 1000);
commitIfTransactionSynchronisationIsInactive();
return entities;
}
private void registerTransactionSynchronisationIfSynchronisationActive() {
if (TransactionSynchronizationManager.isSynchronizationActive()) {
registerTransactionSynchronisationAdapter();
}
}
private void registerTransactionSynchronisationAdapter() {
TransactionSynchronizationManager.registerSynchronization(SolrTransactionSynchronizationAdapterBuilder
.forOperations(this.solrOperations).withDefaultBehaviour());
}
private void commitIfTransactionSynchronisationIsInactive() {
if (!TransactionSynchronizationManager.isSynchronizationActive()) {
this.solrOperations.commit();
}
}
}
and you also need to provide a SolrOperations bean for the right solr core:
#Configuration
public class FooSolrConfig {
#Bean
public SolrOperations getFooSolrOperations(SolrClient solrClient) {
return new SolrTemplate(solrClient, "foo");
}
}
Footnote: auto commit is (to my mind) conceptually incompatible with a transaction. An auto commit is a promise from solr that it will try to start to write it to disk within a certain time limit. Many things might stop that from actually happening however - a timely power or hardware failure, errors between the document and the schema, etc. But the client won't know that solr failed to keep its promise, and the transaction will see a success when it actually failed.