Search Results

Search found 9457 results on 379 pages for 'wp engine'.

Page 90/379 | < Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >

  • Custom search engine in asp.net mvc and entity framework

    - by Rahat
    Hi, does anyone have any idea how I can get started building a search engine for my asp.net mvc site using entity framework. I plan to build something like: http://www.carsguide.com.au/search/?N=4294962119++492&type=cars there on the left there is a refine search option panel. What's the best approach to design a model for the UI and optimized query with entity framework.

    Read the article

  • Running a method for infinitely in google app engine/Gwt

    - by sonam
    I am having a a method which listens continuously to a stream from a server and writes that data to datastore in google app which is later on retrieved by other methods. How can i do that in google app engine i.e calling that method one time during the starting of app and having it running for unlimited time without affecting other things. I am new to java world,So please help from that point of view also.How's that done in Java?

    Read the article

  • What does 'engine' refer to in Drupal Theming?

    - by Nick Lowman
    I've been reading about Drupal theming and preprocess functions and noticed they listed engineName_engine_preprocess & engineName_engine_preprocess_hook in the order of preprocess functions but I'm not entirely sure what the engine layer is? I understand about the core, includes, modules and themes. Many thanks

    Read the article

  • looking for a javascript engine

    - by c0f33.alex
    i'm looking for a js engine to that I can (easily) expose C/C++ functions, classes etc. The API should allow changing exposed values from within C++ (by storing some kind of pointer or reference to an object inside js or so...). I've considered using google's v8 but I'm new to it and don't know whether it will satisfy my requirements. Can someone tell me whether I should stick to v8 or try something else?

    Read the article

  • fastest engine to convert PDF into PNG

    - by skyde
    I would like to know which of the opensource PDF engine can convert a pdf into a image the fastest. I don't care about the quality of the result (antialiasing ...) For my project it need to be very very fast. I would probably need to build my own but i dont wan't to start from scratch.

    Read the article

  • PHP: Which DB/DB Engine supports search well?

    - by KeyStroke
    Hi, I'm starting a site which relies heavily on search. While it's probably going to search basic meta data in the beginning, it might grow to something bigger in the future. So which DB/DB Engine is best in your opinion when it comes to search performance and future scalability? Appreciate your help

    Read the article

  • Zend framework Json engine?

    - by simple
    Is there some kind a engine for Json in the Zend framework, What I mean is some abstraction that all the Json (ajax) responces go through ? in other words some class to controll all the Ajax calls?

    Read the article

  • Lightweight Java reporting engine

    - by tuler
    I'm looking for a lightweight java reporting engine to be embedded in an applet application. My first option was Jasper Reports, but the jar is over 2Mb, a little too heavy (and too bloated) for my needs. I don't know if there is modular jasper distribution, with funcionalities split in several jars (like html rendering, pdf, excel, compilation, runtime, etc). I need to preview the report using Swing and print it. PDF export is a plus.

    Read the article

  • Suggestion for developing search engine

    - by MohamedGooner
    I want to develop a simple search engine, using ASP.NET and C# , where I can search for a word which contained in a very big text (like the Holy Bible or something like that), then the program shows the user where the word is. I have no idea about in which database I can put this large text and using which method will I search for a word. Any suggestions will help me, and if anyone have a tutorial for anything similar it will benefit me.

    Read the article

  • Firefox engine library

    - by martin.malek
    Hi, I'm now using AxWebBrowser component to get DOM from web page and find used styles on each element. Unfortunatelly this is not working perfectly and some elements doesn't return correct data. I'm thinking about if it's possible to use engine from firefox? Is there some dll library I can use, navigate to the page and go throw DOM of the page?

    Read the article

  • What is dbReferenceProperty?

    - by user246114
    Hi, In the python app engine docs, I see something called dbReferenceProperty. I can't understand what it is, or how it's used. I'm using the java interface to app engine, so I'm not sure if there's an equivalent. I'm interested in it because it sounds like some sort of pseudo-join, where we can point a property of a class to some other object's value - something like if we had: class User { private String mPhotoUrl; private String mPhone; private String mState; private String mCountry; .. etc .. } class UserLite { @ReferenceProperty User.mPhotoUrl; private String mPhotoUrl; } then if we had to update a User object's mPhotoUrl value, the change would somehow propagate out to all UserLite instances referencing it, rather than having to update every UserLite object instance manually, Thanks

    Read the article

  • ABBYY Mobile OCR Engine for Iphone

    - by Heavy Bytes
    I am looking to use/buy a OCR solution for my next iPhone app. Searching through the answers on this site didn't really help me a lot. Did anybody ever use ABBYY Mobile OCR Engine for iPhone? What interests me is how good is it (recognition) and how much does it cost? Thank you.

    Read the article

  • Missing sounds in cocos engine!

    - by Demis
    Hello guys, today i took some problem with sounds... I made video before 1st lvl of game, Why after playing the player (with video) in cocos sound engine, game missing sounds (buttons sounds etc) But music work good.

    Read the article

  • Does migrating a site that is 99% several megs of static HTML from Apache to Google App Enging make

    - by JonathanHayward
    I have a large site of mostly static content, and I have entertained migrating to Google App Engine. I am wondering, not so much if it is possible as whether that is cutting a steak with a screwdriver. I see a way to do it in Django that has a bad design smell. Does migrating a literature site that is largely static HTML from Apache to Google App Engine make sense? I'm not specifically asking for a comparison to Nginx or Cherokee; I am interested in whether migrating from a traditional web hosting solution to a more cloudy type of solution recommends itself. The site is JonathansCorner.com, and is presently unavailable ("the magic blue smoke has escaped").

    Read the article

  • Can search engine robots read file with permission 640?

    - by dkjain
    I am on a shared web hosting linux server. I want search engine robots/spiders to be able to read the robots.txt but not any one typing www.mysite.com/robots.txt. As per the following google group post, the user specifies that by setting file permission to 640, it's possible to deny access to robots.txt file by the world but still enable search engine robots to read them. Is that true? If not how it's possible to deny general public access to robots.txt but still allow Search engine robots to read them.

    Read the article

  • Does Your Business Really Need a Search Engine Optimization Specialist?

    If you're an individual or an organization planning to employ a search engine optimization professional, you might first want to consider the possibility of doing this work yourself. Certainly, a search engine optimization consultant can boost your site and perhaps help save you time and effort, yet the fact is that SEO is hardly an advanced science, and there are just a handful of authentic professionals within the field. So, if you depend on somebody else to be in charge of your search engine optimization, there's a high probability that the person will not possess a great deal more knowledge than you. And if you lack any knowledge, all the relevant information is easy to obtain.

    Read the article

  • WordPress not resizing images with Nginx + php-fpm and other issues

    - by Julian Fernandes
    Recently i setup a Ubuntu 12.04 VPS with 512mb/1ghz CPU, Nginx + php-fpm + Varnish + APC + Percona's MySQL server + CloudFlare Pro for our Ubuntu LoCo Team's WordPress blog. The blog get about 3~4k daily hits, use about 180MB and 8~20% CPU. Everything seems to be working insanely fast... page load is really good and is about 16x faster than any of our competitors... but there is one problem. When we upload a image, WordPress don't resize it, so all we can do it insert the full image in the post. If the imagem have, let's say, 30kb, it resize fine... but if the image have 100kb+, it won't... In nginx error logs i see this: upstream timed out (110: Connection timed out) while reading response header from upstream, client: 150.162.216.64, server: www.ubuntubrsc.com, request: "POST /wp-admin/async-upload.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "www.ubuntubrsc.com", referrer: "http://www.ubuntubrsc.com/wp-admin/media-upload.php?post_id=2668&" It seems to be related with the issue, but i dunno. When that timeout happens, i started to get it when i'm trying to view a post too: upstream timed out (110: Connection timed out) while reading response header from upstream, client: 150.162.216.64, server: www.ubuntubrsc.com, request: "GET /tutoriais-gimp-6-adicionando-aplicando-novos-pinceis.html HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "www.ubuntubrsc.com", referrer: "http://www.ubuntubrsc.com/" And only a restart of php5-fpm fix it. I tryed increasing some timeouts and stuffs but it did not worked, so i guess it's some kind of limitation i did not figured yet. Could someone help me with it, please? /etc/nginx/nginx.conf: user www-data; worker_processes 1; pid /var/run/nginx.pid; events { worker_connections 1024; use epoll; multi_accept on; } http { ## # Basic Settings ## sendfile on; tcp_nopush on; tcp_nodelay off; keepalive_timeout 15; keepalive_requests 2000; types_hash_max_size 2048; server_tokens off; server_name_in_redirect off; open_file_cache max=1000 inactive=300s; open_file_cache_valid 360s; open_file_cache_min_uses 2; open_file_cache_errors off; server_names_hash_bucket_size 64; # server_name_in_redirect off; client_body_buffer_size 128K; client_header_buffer_size 1k; client_max_body_size 2m; large_client_header_buffers 4 8k; client_body_timeout 10m; client_header_timeout 10m; send_timeout 10m; include /etc/nginx/mime.types; default_type application/octet-stream; ## # Logging Settings ## error_log /var/log/nginx/error.log; access_log off; ## # CloudFlare's IPs (uncomment when site goes live) ## set_real_ip_from 204.93.240.0/24; set_real_ip_from 204.93.177.0/24; set_real_ip_from 199.27.128.0/21; set_real_ip_from 173.245.48.0/20; set_real_ip_from 103.22.200.0/22; set_real_ip_from 141.101.64.0/18; set_real_ip_from 108.162.192.0/18; set_real_ip_from 190.93.240.0/20; real_ip_header CF-Connecting-IP; set_real_ip_from 127.0.0.1/32; ## # Gzip Settings ## gzip on; gzip_disable "msie6"; gzip_vary on; gzip_proxied any; gzip_comp_level 9; gzip_min_length 1000; gzip_proxied expired no-cache no-store private auth; gzip_buffers 32 8k; # gzip_http_version 1.1; gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript; ## # nginx-naxsi config ## # Uncomment it if you installed nginx-naxsi ## #include /etc/nginx/naxsi_core.rules; ## # nginx-passenger config ## # Uncomment it if you installed nginx-passenger ## #passenger_root /usr; #passenger_ruby /usr/bin/ruby; ## # Virtual Host Configs ## include /etc/nginx/conf.d/*.conf; include /etc/nginx/sites-enabled/*; } /etc/nginx/fastcgi_params: fastcgi_param QUERY_STRING $query_string; fastcgi_param REQUEST_METHOD $request_method; fastcgi_param CONTENT_TYPE $content_type; fastcgi_param CONTENT_LENGTH $content_length; fastcgi_param SCRIPT_FILENAME $request_filename; fastcgi_param SCRIPT_NAME $fastcgi_script_name; fastcgi_param REQUEST_URI $request_uri; fastcgi_param DOCUMENT_URI $document_uri; fastcgi_param DOCUMENT_ROOT $document_root; fastcgi_param SERVER_PROTOCOL $server_protocol; fastcgi_param GATEWAY_INTERFACE CGI/1.1; fastcgi_param SERVER_SOFTWARE nginx/$nginx_version; fastcgi_param REMOTE_ADDR $remote_addr; fastcgi_param REMOTE_PORT $remote_port; fastcgi_param SERVER_ADDR $server_addr; fastcgi_param SERVER_PORT $server_port; fastcgi_param SERVER_NAME $server_name; fastcgi_param HTTPS $https; fastcgi_send_timeout 180; fastcgi_read_timeout 180; fastcgi_buffer_size 128k; fastcgi_buffers 256 4k; # PHP only, required if PHP was built with --enable-force-cgi-redirect fastcgi_param REDIRECT_STATUS 200; /etc/nginx/sites-avaiable/default: ## # DEFAULT HANDLER # ubuntubrsc.com ## server { listen 8080; # Make site available from main domain server_name www.ubuntubrsc.com; # Root directory root /var/www; index index.php index.html index.htm; include /var/www/nginx.conf; access_log off; location / { try_files $uri $uri/ /index.php?q=$uri&$args; } location = /favicon.ico { log_not_found off; access_log off; } location = /robots.txt { allow all; log_not_found off; access_log off; } location ~ /\. { deny all; access_log off; log_not_found off; } location ~* ^/wp-content/uploads/.*.php$ { deny all; access_log off; log_not_found off; } rewrite /wp-admin$ $scheme://$host$uri/ permanent; error_page 404 = @wordpress; log_not_found off; location @wordpress { include /etc/nginx/fastcgi_params; fastcgi_pass unix:/var/run/php5-fpm.sock; fastcgi_param SCRIPT_NAME /index.php; fastcgi_param SCRIPT_FILENAME $document_root/index.php; } location ~ \.php$ { try_files $uri =404; include /etc/nginx/fastcgi_params; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; if (-f $request_filename) { fastcgi_pass unix:/var/run/php5-fpm.sock; } } } server { listen 8080; server_name ubuntubrsc.* www.ubuntubrsc.net www.ubuntubrsc.org www.ubuntubrsc.com.br www.ubuntubrsc.info www.ubuntubrsc.in; return 301 $scheme://www.ubuntubrsc.com$request_uri; } /var/www/nginx.conf: # BEGIN W3TC Minify cache location ~ /wp-content/w3tc/min.*\.js$ { types {} default_type application/x-javascript; expires modified 31536000s; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; add_header Vary "Accept-Encoding"; add_header Pragma "public"; add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate"; } location ~ /wp-content/w3tc/min.*\.css$ { types {} default_type text/css; expires modified 31536000s; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; add_header Vary "Accept-Encoding"; add_header Pragma "public"; add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate"; } location ~ /wp-content/w3tc/min.*js\.gzip$ { gzip off; types {} default_type application/x-javascript; expires modified 31536000s; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; add_header Vary "Accept-Encoding"; add_header Pragma "public"; add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate"; add_header Content-Encoding gzip; } location ~ /wp-content/w3tc/min.*css\.gzip$ { gzip off; types {} default_type text/css; expires modified 31536000s; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; add_header Vary "Accept-Encoding"; add_header Pragma "public"; add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate"; add_header Content-Encoding gzip; } # END W3TC Minify cache # BEGIN W3TC Browser Cache gzip on; gzip_types text/css application/x-javascript text/x-component text/richtext image/svg+xml text/plain text/xsd text/xsl text/xml image/x-icon; location ~ \.(css|js|htc)$ { expires 31536000s; add_header Pragma "public"; add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate"; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; } location ~ \.(html|htm|rtf|rtx|svg|svgz|txt|xsd|xsl|xml)$ { expires 3600s; add_header Pragma "public"; add_header Cache-Control "max-age=3600, public, must-revalidate, proxy-revalidate"; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; try_files $uri $uri/ $uri.html /index.php?$args; } location ~ \.(asf|asx|wax|wmv|wmx|avi|bmp|class|divx|doc|docx|eot|exe|gif|gz|gzip|ico|jpg|jpeg|jpe|mdb|mid|midi|mov|qt|mp3|m4a|mp4|m4v|mpeg|mpg|mpe|mpp|otf|odb|odc|odf|odg|odp|ods|odt|ogg|pdf|png|pot|pps|ppt|pptx|ra|ram|svg|svgz|swf|tar|tif|tiff|ttf|ttc|wav|wma|wri|xla|xls|xlsx|xlt|xlw|zip)$ { expires 31536000s; add_header Pragma "public"; add_header Cache-Control "max-age=31536000, public, must-revalidate, proxy-revalidate"; add_header X-Powered-By "W3 Total Cache/0.9.2.5b"; } # END W3TC Browser Cache # BEGIN W3TC Minify core rewrite ^/wp-content/w3tc/min/w3tc_rewrite_test$ /wp-content/w3tc/min/index.php?w3tc_rewrite_test=1 last; set $w3tc_enc ""; if ($http_accept_encoding ~ gzip) { set $w3tc_enc .gzip; } if (-f $request_filename$w3tc_enc) { rewrite (.*) $1$w3tc_enc break; } rewrite ^/wp-content/w3tc/min/(.+\.(css|js))$ /wp-content/w3tc/min/index.php?file=$1 last; # END W3TC Minify core # BEGIN W3TC Skip 404 error handling by WordPress for static files if (-f $request_filename) { break; } if (-d $request_filename) { break; } if ($request_uri ~ "(robots\.txt|sitemap(_index)?\.xml(\.gz)?|[a-z0-9_\-]+-sitemap([0-9]+)?\.xml(\.gz)?)") { break; } if ($request_uri ~* \.(css|js|htc|htm|rtf|rtx|svg|svgz|txt|xsd|xsl|xml|asf|asx|wax|wmv|wmx|avi|bmp|class|divx|doc|docx|eot|exe|gif|gz|gzip|ico|jpg|jpeg|jpe|mdb|mid|midi|mov|qt|mp3|m4a|mp4|m4v|mpeg|mpg|mpe|mpp|otf|odb|odc|odf|odg|odp|ods|odt|ogg|pdf|png|pot|pps|ppt|pptx|ra|ram|svg|svgz|swf|tar|tif|tiff|ttf|ttc|wav|wma|wri|xla|xls|xlsx|xlt|xlw|zip)$) { return 404; } # END W3TC Skip 404 error handling by WordPress for static files # BEGIN Better WP Security location ~ /\.ht { deny all; } location ~ wp-config.php { deny all; } location ~ readme.html { deny all; } location ~ readme.txt { deny all; } location ~ /install.php { deny all; } set $susquery 0; set $rule_2 0; set $rule_3 0; rewrite ^wp-includes/(.*).php /not_found last; rewrite ^/wp-admin/includes(.*)$ /not_found last; if ($request_method ~* "^(TRACE|DELETE|TRACK)"){ return 403; } set $rule_0 0; if ($request_method ~ "POST"){ set $rule_0 1; } if ($uri ~ "^(.*)wp-comments-post.php*"){ set $rule_0 2$rule_0; } if ($http_user_agent ~ "^$"){ set $rule_0 4$rule_0; } if ($rule_0 = "421"){ return 403; } if ($args ~* "\.\./") { set $susquery 1; } if ($args ~* "boot.ini") { set $susquery 1; } if ($args ~* "tag=") { set $susquery 1; } if ($args ~* "ftp:") { set $susquery 1; } if ($args ~* "http:") { set $susquery 1; } if ($args ~* "https:") { set $susquery 1; } if ($args ~* "(<|%3C).*script.*(>|%3E)") { set $susquery 1; } if ($args ~* "mosConfig_[a-zA-Z_]{1,21}(=|%3D)") { set $susquery 1; } if ($args ~* "base64_encode") { set $susquery 1; } if ($args ~* "(%24&x)") { set $susquery 1; } if ($args ~* "(\[|\]|\(|\)|<|>|ê|\"|;|\?|\*|=$)"){ set $susquery 1; } if ($args ~* "(&#x22;|&#x27;|&#x3C;|&#x3E;|&#x5C;|&#x7B;|&#x7C;|%24&x)"){ set $susquery 1; } if ($args ~* "(%0|%A|%B|%C|%D|%E|%F|127.0)") { set $susquery 1; } if ($args ~* "(globals|encode|localhost|loopback)") { set $susquery 1; } if ($args ~* "(request|select|insert|concat|union|declare)") { set $susquery 1; } if ($http_cookie !~* "wordpress_logged_in_" ) { set $susquery "${susquery}2"; set $rule_2 1; set $rule_3 1; } if ($susquery = 12) { return 403; } # END Better WP Security /etc/php5/fpm/php-fpm.conf: pid = /var/run/php5-fpm.pid error_log = /var/log/php5-fpm.log emergency_restart_threshold = 3 emergency_restart_interval = 1m process_control_timeout = 10s events.mechanism = epoll /etc/php5/fpm/php.ini (only options i changed): open_basedir ="/var/www/" disable_functions = pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,dl,system,shell_exec,fsockopen,parse_ini_file,passthru,popen,proc_open,proc_close,shell_exec,show_source,symlink,proc_close,proc_get_status,proc_nice,proc_open,proc_terminate,shell_exec ,highlight_file,escapeshellcmd,define_syslog_variables,posix_uname,posix_getpwuid,apache_child_terminate,posix_kill,posix_mkfifo,posix_setpgid,posix_setsid,posix_setuid,escapeshellarg,posix_uname,ftp_exec,ftp_connect,ftp_login,ftp_get,ftp_put,ftp_nb_fput,ftp_raw,ftp_rawlist,ini_alter,ini_restore,inject_code,syslog,openlog,define_syslog_variables,apache_setenv,mysql_pconnect,eval,phpAds_XmlRpc,phpA ds_remoteInfo,phpAds_xmlrpcEncode,phpAds_xmlrpcDecode,xmlrpc_entity_decode,fp,fput,virtual,show_source,pclose,readfile,wget expose_php = off max_execution_time = 30 max_input_time = 60 memory_limit = 128M display_errors = Off post_max_size = 2M allow_url_fopen = off default_socket_timeout = 60 APC settings: [APC] apc.enabled = 1 apc.shm_segments = 1 apc.shm_size = 64M apc.optimization = 0 apc.num_files_hint = 4096 apc.ttl = 60 apc.user_ttl = 7200 apc.gc_ttl = 0 apc.cache_by_default = 1 apc.filters = "" apc.mmap_file_mask = "/tmp/apc.XXXXXX" apc.slam_defense = 0 apc.file_update_protection = 2 apc.enable_cli = 0 apc.max_file_size = 10M apc.stat = 1 apc.write_lock = 1 apc.report_autofilter = 0 apc.include_once_override = 0 apc.localcache = 0 apc.localcache.size = 512 apc.coredump_unmap = 0 apc.stat_ctime = 0 /etc/php5/fpm/pool.d/www.conf user = www-data group = www-data listen = /var/run/php5-fpm.sock listen.owner = www-data listen.group = www-data listen.mode = 0666 pm = ondemand pm.max_children = 5 pm.process_idle_timeout = 3s; pm.max_requests = 50 I also started to get 404 errors in front page if i use W3 Total Cache's Page Cache (Disk Enhanced). It worked fine untill somedays ago, and then, out of nowhere, it started to happen. Tonight i will disable my mobile plugin and activate only W3 Total Cache to see if it's a conflict with them... And to finish all this, i have been getting this error: PHP Warning: apc_store(): Unable to allocate memory for pool. in /var/www/wp-content/plugins/w3-total-cache/lib/W3/Cache/Apc.php on line 41 I already modifed my APC settings, but no sucess. So... could anyone help me with those issuees, please? Ooohh... if it helps, i instaled PHP like this: sudo apt-get install php5-fpm php5-suhosin php-apc php5-gd php5-imagick php5-curl And Nginx from the official PPA. Sorry for my bad english and thanks for your time people! (:

    Read the article

  • Committed JDO writes do not apply on local GAE HRD, or possibly reused transaction

    - by eeeeaaii
    I'm using JDO 2.3 on app engine. I was using the Master/Slave datastore for local testing and recently switched over to using the HRD datastore for local testing, and parts of my app are breaking (which is to be expected). One part of the app that's breaking is where it sends a lot of writes quickly - that is because of the 1-second limit thing, it's failing with a concurrent modification exception. Okay, so that's also to be expected, so I have the browser retry the writes again later when they fail (maybe not the best hack but I'm just trying to get it working quickly). But a weird thing is happening. Some of the writes which should be succeeding (the ones that DON'T get the concurrent modification exception) are also failing, even though the commit phase completes and the request returns my success code. I can see from the log that the retried requests are working okay, but these other requests that seem to have committed on the first try are, I guess, never "applied." But from what I read about the Apply phase, writing again to that same entity should force the apply... but it doesn't. Code follows. Some things to note: I am attempting to use automatic JDO caching. So this is where JDO uses memcache under the covers. This doesn't actually work unless you wrap everything in a transaction. all the requests are doing is reading a string out of an entity, modifying part of the string, and saving that string back to the entity. If these requests weren't in transactions, you'd of course have the "dirty read" problem. But with transactions, isolation is supposed to be at the level of "serializable" so I don't see what's happening here. the entity being modified is a root entity (not in a group) I have cross-group transactions enabled Another weird thing is happening. If the concurrent modification thing happens, and I subsequently edit more than 5 more entities (this is the max for cross-group transactions), then nothing happens right away, but when I stop and restart the server I get "IllegalArgumentException: operating on too many entity groups in a single transaction". Could it be possible that the PMF is returning the same PersistenceManager every time, or the PM is reusing the same transaction every time? I don't see how I could possibly get the above error otherwise. The code inside the transaction just edits one root entity. I can't think of any other way that GAE would give me the "too many entity groups" error. The relevant code (this is a simplified version) PersistenceManager pm = PMF.getManager(); Transaction tx = pm.currentTransaction(); String responsetext = ""; try { tx.begin(); // I have extra calls to "makePersistent" because I found that relying // on pm.close didn't always write the objects to cache, maybe that // was only a DataNucleus 1.x issue though Key userkey = obtainUserKeyFromCookie(); User u = pm.getObjectById(User.class, userkey); pm.makePersistent(u); // to make sure it gets cached for next time Key mapkey = obtainMapKeyFromQueryString(); // this is NOT a java.util.Map, just FYI Map currentmap = pm.getObjectById(Map.class, mapkey); Text mapData = currentmap.getMapData(); // mapData is JSON stored in the entity Text newMapData = parseModifyAndReturn(mapData); // transform the map currentmap.setMapData(newMapData); // mutate the Map object pm.makePersistent(currentmap); // make sure to persist so there is a cache hit tx.commit(); responsetext = "OK"; } catch (JDOCanRetryException jdoe) { // log jdoe responsetext = "RETRY"; } catch (Exception e) { // log e responsetext = "ERROR"; } finally { if (tx.isActive()) { tx.rollback(); } pm.close(); } resp.getWriter().println(responsetext); EDIT: so I have verified that it fails after exactly 5 transactions. Here's what I do: I create a Foo (root entity), do a bunch of concurrent operations on that Foo, and some fail and get retried, and some commit but don't apply (as described above). Then, I start creating more Foos, and do a few operations on those new Foos. If I only create four Foos, stopping and restarting app engine does NOT give me the IllegalArgumentException. However if I create five Foos (which is the limit for cross-group transactions), then when I stop and restart app engine, I do get the exception. So it seems that somehow these new Foos I am creating are counting toward the limit of 5 max entities per transaction, even though they are supposed to be handled by separate transactions. It's as if a transaction is still open and is being reused by the servlet when it handles the new requests for the 2nd through 5th Foos. EDIT2: it looks like the IllegalArgument thing is independent of the other bug. In other words, it always happens when I create five Foos, even if I don't get the concurrent modification exception. I don't know if it's a symptom of the same problem or if it's unrelated. EDIT3: I found out what was causing the (unrelated) IllegalArgumentException, it was a dumb mistake on my part. But the other issue is still happening. EDIT4: added pseudocode for the datastore access EDIT5: I am pretty sure I know why this is happening, but I will still award the bounty to anyone who can confirm it. Basically, I think the problem is that transactions are not really implemented in the local version of the datastore. References: https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/gVMS1dFSpcU https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/deGasFdIO-M https://groups.google.com/forum/?hl=en&fromgroups=#!msg/google-appengine-java/4YuNb6TVD6I/gSttMmHYwo0J Because transactions are not implemented, rollback is essentially a no-op. Therefore, I get a dirty read when two transactions try to modify the record at the same time. In other words, A reads the data and B reads the data at the same time. A attempts to modify the data, and B attempts to modify a different part of the data. A writes to the datastore, then B writes, obliterating A's changes. Then B is "rolled back" by app engine, but since rollbacks are a no-op when running on the local datastore, B's changes stay, and A's do not. Meanwhile, since B is the thread that threw the exception, the client retries B, but does not retry A (since A was supposedly the transaction that succeeded).

    Read the article

< Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >