How do I avoid getting duplicate key errors when using findOrSaveBy dynamic finders in Grails? - grails

Question

In a concurrent situation (asynchronous file uploads) where I try to create (or reuse) and attach keyword tags to images in an image library application i get a Unique index or primary key violation when creating Tag domain objects.
The controller calls a service method to add an image to the library and also the keyword tags that belongs to it.
Am I going about this the wrong way or am I missing something?
I'm currently using Grails 2.3.5.
Code:
class ImageAssetService {
def addTagToImage(ImageAsset imageAsset, String kw, String locale) {
def tagName = kw.toLowerCase(Locale.forLanguageTag(locale))
// OFFENDING LINE NEXT
def tag = Tag.findOrSaveByNameAndLocale(tagName, locale, [lock: true])
imageAsset.addToTags(tag)
if(!imageAsset.save()) {
throw new ImageAssetException()
}
imageAsset
}
def addTagsToImage(ImageAsset imageAsset, Set<String> keywords, String locale) {
keywords.each { kw ->
addTagToImage(imageAsset, kw, locale)
}
imageAsset
}
// CONTROLLER CALLS THIS METHOD
def addImageAsset(InputStream inputStream, String filename, long fileSize, long authorId, String timeZoneOriginal, String heading, String description, Set tags, String imageCollectionName) {
// Create the ImageAsset domain object
ImageAsset imageAsset = new ImageAsset(
filename: filename,
fileSize: fileSize,
author: Author.get(authorId),
timeZoneOriginal: TimeZone.getTimeZone(timeZoneOriginal),
heading: heading,
description: description
).save()
// Add any tags
addTagsToImage(imageAsset, tags, 'en')
/*
...
CODE REMOVED FOR BREVITY
....
*/
return imageAsset
}
}
class Tag {
String locale
String name
static hasMany = [ translations : Tag, synonyms : Tag ]
void setName(String name) { this.#name = name.toLowerCase() }
static constraints = {
locale unique: ['name']
}
static belongsTo = ImageAsset
static searchable = {
except = ['locale']
name boost: 2.0
translations component: [prefix: 'translations_', maxDepth: 2]
synonyms component: [prefix: 'synonyms_', maxDepth: 2]
}
static mapping = {
table 'tags'
}
}
class ImageAsset {
String filename
String heading
String description
String place
String city
String country
String gps
long fileSize = 0
int pixelWidth = 0
int pixelHeight = 0
Date dateTimeOriginal
TimeZone timeZoneOriginal
boolean enabled = true
Date dateCreated
static belongsTo = [
Author,
ConceptualImageCategory,
RepresentativeImageCategory,
ImageCollection
]
static hasOne = [ author : Author ]
static hasMany = [
conceptualCategories : ConceptualImageCategory,
representativeCategories : RepresentativeImageCategory,
collections : ImageCollection,
metadata : Metadata,
tags : Tag
]
static constraints = {
filename blank: false
heading nullable: true
description nullable: true
place nullable: true
city nullable: true
country nullable: true
gps nullable: true
pixelWidth nullable: true
pixelHeight nullable: true
dateTimeOriginal nullable: true
timeZoneOriginal nullable: true
}
static mapping = {
description type: 'text'
}
static searchable = {
//only = ['filename', 'heading', 'description', 'tags', 'metadata']
author component: [prefix: 'author_']
tags component: [prefix: 'tags_']
metadata component: [prefix: 'metadata_']
}
}
Error message:
Unique index or primary key violation: "CONSTRAINT_INDEX_27 ON PUBLIC.TAGS(NAME, LOCALE) VALUES ( /* key:11 */ 895, 0, 'en', 'work')"; SQL statement:
insert into tags (id, version, locale, name) values (null, ?, ?, ?) [23505-173]. Stacktrace follows:
Message: Unique index or primary key violation: "CONSTRAINT_INDEX_27 ON PUBLIC.TAGS(NAME, LOCALE) VALUES ( /* key:11 */ 895, 0, 'en', 'work')"; SQL statement:
insert into tags (id, version, locale, name) values (null, ?, ?, ?) [23505-173]
Line | Method
->> 331 | getJdbcSQLException in org.h2.message.DbException
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
| 171 | get in ''
| 148 | get . . . . . . . . . . in ''
| 101 | getDuplicateKeyException in org.h2.index.BaseIndex
| 68 | add . . . . . . . . . . in org.h2.index.TreeIndex
| 52 | add in org.h2.index.MultiVersionIndex
| 125 | addRow . . . . . . . . . in org.h2.table.RegularTable
| 127 | insertRows in org.h2.command.dml.Insert
| 86 | update . . . . . . . . . in ''
| 79 | update in org.h2.command.CommandContainer
| 235 | executeUpdate . . . . . in org.h2.command.Command
| 154 | executeUpdateInternal in org.h2.jdbc.JdbcPreparedStatement
| 140 | executeUpdate . . . . . in ''
| 102 | doCall in org.grails.datastore.gorm.GormStaticApi$_methodMissing_closure2
| 105 | addTagToImage . . . . . in se.originalab.imagedb.ImageAssetService
| 94 | doCall in se.originalab.imagedb.ImageAssetService$_addTagsToImage_closure3
| 93 | addTagsToImage . . . . . in se.originalab.imagedb.ImageAssetService
| 45 | addImageAsset in ''
| 31 | upload . . . . . . . . . in se.originalab.imagedb.UploadController
| 195 | doFilter in grails.plugin.cache.web.filter.PageFragmentCachingFilter
| 63 | doFilter . . . . . . . . in grails.plugin.cache.web.filter.AbstractFilter
| 53 | doFilter in grails.plugin.springsecurity.web.filter.GrailsAnonymousAuthenticationFilter
| 49 | doFilter . . . . . . . . in grails.plugin.springsecurity.web.authentication.RequestHolderAuthenticationFilter
| 82 | doFilter in grails.plugin.springsecurity.web.authentication.logout.MutableLogoutFilter
| 1110 | runWorker . . . . . . . in java.util.concurrent.ThreadPoolExecutor
| 603 | run in java.util.concurrent.ThreadPoolExecutor$Worker
^ 722 | run . . . . . . . . . . in java.lang.Thread

Answer 1

I found a solution myself. I had to break out the creation of a Tag into it's own transaction. Each call to Tag.findOrSaveByNameLocale() is now called through a synchronized service method from the controller. Then I add them to the ImageAsset afterwards.
One problem with this is that if the creation of the ImageAsset fails the Tags will still be persisted, but in my use case this is not a big problem.