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• Database performance benchmark

  - by pablo

  Any good articles out there comparing Oracle vs SQL Server vs MySql in terms of performance? I'd like to know things like: INSERT performance SELECT performance Scalability under heavy load Based on some real examples in order to gain a better understanding about the different RDBMS.

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• Serialization Performance and Google Android

  - by Jomanscool2

  I'm looking for advice to speed up serialization performance, specifically when using the Google Android. For a project I am working on, I am trying to relay a couple hundred objects from a server to the Android app, and am going through various stages to get the performance I need. First I tried a terrible XML parser that I hacked together using Scanner specifically for this project, and that caused unbelievably slow performance when loading the objects (~5 minutes for a 300KB file). I then moved away from that and made my classes implement Serializable and wrote the ArrayList of objects I had to a file. Reading that file into the objects the Android, with the file already downloaded mind you, was taking ~15-30 seconds for the ~100KB serialized file. I still find this completely unacceptable for an Android app, as my app requires loading the data when starting the application. I have read briefly about Externalizable and how it can increase performance, but I am not sure as to how one implements it with nested classes. Right now, I am trying to store an ArrayList of the following class, with the nested classes below it. public class MealMenu implements Serializable{ private String commonsName; private long startMillis, endMillis, modMillis; private ArrayList<Venue> venues; private String mealName; } And the Venue class: public class Venue implements Serializable{ private String name; private ArrayList<FoodItem> foodItems; } And the FoodItem class: public class FoodItem implements Serializable{ private String name; private boolean vegan; private boolean vegetarian; } IF Externalizable is the way to go to increase performance, is there any information as to how java calls the methods in the objects when you try to write it out? I am not sure if I need to implement it in the parent class, nor how I would go about serializing the nested objects within each object.

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• PHP Performance Metrics

  - by bigstylee

  I am currently developing a PHP MVC Framework for a personal project. While I am developing the framework I am interested to see any notable performance by implementing different techniques for optimization. I have implemented a crude BenchMark class that logs mircotime. The problem is I have no frame of reference for execution times. I am very near the beginnig of this project with a database connection and a few queries but no output (bar some debugging text and BenchMark log). I have a current execution time of 0.01917 seconds. I was expecting this to be lower but as I said before I have no frame of reference. I appreciate there are many variables to take into account when juding performance but I am hoping to find some sort of metric to a) techniques to measure performance for example requests per second and b) compare results for example; how a "moderately" sized PHP application on a "standard" webserver will perform. I appreciate "moderately" and "standard" are very subjective words so perhaps a table of known execution times for a particular application (eg StackOverFlow's executing time). What are other techniques of measuring performance are there other than execution time? When looking at MVC Framework Performance Comparisom it talks about Requests Per Second (RPS). How is this calculated? I am guessing with my current execution time of 0.01917 seconds can handle 52 RPS (= 1 / 0.01917 ). This seems to be significantly lower than that quoted on the graph especially when you consider my current limited funcitonality.

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• Does performance even matter anymore? [closed]

  - by Jeff Dahmer

  The performance differences between C/C++ and C# are astounding. An ASP.NET page loads in 1/8 the time that a PHP script does haha.... WPF, aka " The Future ", (you know it will be, all the companies are gonna want cool looking desktop apps, don't kid yourself.) And it has huge performance hits just to start up. We've let Microsoft make us as developers lazy! Why do I hate this, it's such a good thing? Are we at a point in time where the majority of computers can handle this kinda crap? I remember when performance used to matter. Anyways, I'm writing a .NET library and ever since I found out LINQ is slower than traditional delegates which is slower than the normal procedural code... well it's a guilty evil I feel for every LINQ query I write, because they are so beautiful. Am I just too much of a performance stickler? Or just too big of a nerd?

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• Will SQL Server Partitioning increase performance without changing filegroups

  - by Tom

  Scenario I have a 10 million row table. I partition it into 10 partitions, which results in 1 million rows per partition but I do not do anything else (like move the partitions to different file groups or spindles) Will I see a performance increase? Is this in effect like creating 10 smaller tables? If I have queries that perform key lookups or scans, will the performance increase as if they were operating against a much smaller table? I'm trying to understand how partitioning is different from just having a well indexed table, and where it can be used to improve performance. Would a better scenario be to move the old data (using partition switching) out of the primary table to a read only archive table? Is having a table with a 1 million row partition and a 9 million row partition analagous (performance wise) to moving the 9 million rows to another table and leaving only 1 million rows in the original table?

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• WPF: Improving Performance for Running on Older PCs

  - by Phil Sandler

  So, I'm building a WPF app and did a test deployment today, and found that it performed pretty poorly. I was surprised, as we are really not doing much in the way of visual effects or animations. I deployed on two machines: the fastest and the slowest that will need to run the application (the slowest PC has an Intel Celeron 1.80GHz with 2GB RAM). The application ran pretty well on the faster machine, but was choppy on the slower machine. And when I say "choppy", I mean the cursor jumped even just passing it over any open window of the app that had focus. I opened the Task Manager Performance window, and could see that the CPU usage jumped whenever the app had focus and the cursor was moving over it. If I gave focus to another (e.g. Excel), the CPU usage went back down after a second. This happened on both machines, but the choppiness was only noticeable on the slower machine. I had very limited time to tinker on the deployment machines, so didn't do a lot of detailed testing. The app runs fine on my development machine, but I also see the CPU spiking up to 10% there, just running the cursor over the window. I downloaded the WPF performance tool from MS and have been tinkering with it (on my dev machine). The docs say this about the "Frame Rate" metric in the Perforator tool: For applications without animation, this value should be near 0. The app is not doing any heavy animation, but the frame rate stays near 50 when the cursor is over any window. The screens I tested on have column headers in a grid that "highlight" and buttons that change color and appearance when scrolled over. Even moving the mouse on blank areas of the windows cause the same Frame rate and CPU usage (doesn't seem to be related to these minor animations). (Also, I am unable to figure out how to get anything but the two default tools--Perforator and Visual Profiler--installed into the WPF performance tool. That is probably a separate question). I also have Redgate's profiling tool, but I'm not sure if that can shed any light on rendering performance. So, I realize this is not an easy thing to troubleshoot without specifics or sample code (which I can't post). My questions are: What are some general things to look for (or avoid) in the code to improve performance? What steps can I take using the WPF performance tool to narrow down the problem? Is the PC spec listed above (Intel Celeron 1.80GHz with 2GB RAM) too slow to be running even vanilla WPF applications?

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• Auditing front end performance on web application

  - by user1018494

  I am currently trying to performance tune the UI of a company web application. The application is only ever going to be accessed by staff, so the speed of the connection between the server and client will always be considerably more than if it was on the internet. I have been using performance auditing tools such as Y Slow! and Google Chrome's profiling tool to try and highlight areas that are worth targeting for investigation. However, these tools are written with the internet in mind. For example, the current suggestions from a Google Chrome audit of the application suggests is as follows: Network Utilization Combine external CSS (Red warning) Combine external JavaScript (Red warning) Enable gzip compression (Red warning) Leverage browser caching (Red warning) Leverage proxy caching (Amber warning) Minimise cookie size (Amber warning) Parallelize downloads across hostnames (Amber warning) Serve static content from a cookieless domain (Amber warning) Web Page Performance Remove unused CSS rules (Amber warning) Use normal CSS property names instead of vendor-prefixed ones (Amber warning) Are any of these bits of advice totally redundant given the connection speed and usage pattern? The users will be using the application frequently throughout the day, so it doesn't matter if the initial hit is large (when they first visit the page and build their cache) so long as a minimal amount of work is done on future page views. For example, is it worth the effort of combining all of our CSS and JavaScript files? It may speed up the initial page view, but how much of a difference will it really make on subsequent page views throughout the working day? I've tried searching for this but all I keep coming up with is the standard internet facing performance advice. Any advice on what to focus my performance tweaking efforts on in this scenario, or other auditing tool recommendations, would be much appreciated.

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• How to improve Varnish performance?

  - by Darkseal

  We're experiencing a strange problem with our current Varnish configuration. 4x Web Servers (IIS 6.5 on Windows 2003 Server, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB RAM) 3x Varnish Servers (varnish-3.0.3 revision 9e6a70f on Ubuntu 12.04.2 LTS - 64 bit/precise, Kernel Linux 3.2.0-29-generic, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB RAM) The Varnish Servers performance are awfully bad in general, to the point that if we shut down one of them the other two are unable to fullfill all the requests and start to skip beats resulting in pending requests, timeouts, 404, etc. What can we do to improve our Varnish performance? Considering that we're getting less than 5k request per seconds during our max peak, we should be able to serve our pages even with a single one of them without any problem. We use a standard, vanilla CFG, as shown by this varnishadm param.show output: acceptor_sleep_decay 0.900000 [] acceptor_sleep_incr 0.001000 [s] acceptor_sleep_max 0.050000 [s] auto_restart on [bool] ban_dups on [bool] ban_lurker_sleep 0.010000 [s] between_bytes_timeout 60.000000 [s] cc_command "exec gcc -std=gnu99 -g -O2 -pthread -fpic -shared - Wl,-x -o %o %s" cli_buffer 8192 [bytes] cli_timeout 20 [seconds] clock_skew 10 [s] connect_timeout 0.700000 [s] critbit_cooloff 180.000000 [s] default_grace 10.000000 [seconds] default_keep 0.000000 [seconds] default_ttl 120.000000 [seconds] diag_bitmap 0x0 [bitmap] esi_syntax 0 [bitmap] expiry_sleep 1.000000 [seconds] fetch_chunksize 128 [kilobytes] fetch_maxchunksize 262144 [kilobytes] first_byte_timeout 60.000000 [s] group varnish (113) gzip_level 6 [] gzip_memlevel 8 [] gzip_stack_buffer 32768 [Bytes] gzip_tmp_space 0 [] gzip_window 15 [] http_gzip_support off [bool] http_max_hdr 64 [header lines] http_range_support on [bool] http_req_hdr_len 8192 [bytes] http_req_size 32768 [bytes] http_resp_hdr_len 8192 [bytes] http_resp_size 32768 [bytes] idle_send_timeout 60 [seconds] listen_address :80 listen_depth 1024 [connections] log_hashstring on [bool] log_local_address off [bool] lru_interval 2 [seconds] max_esi_depth 5 [levels] max_restarts 4 [restarts] nuke_limit 50 [allocations] pcre_match_limit 10000 [] pcre_match_limit_recursion 10000 [] ping_interval 3 [seconds] pipe_timeout 60 [seconds] prefer_ipv6 off [bool] queue_max 100 [%] rush_exponent 3 [requests per request] saintmode_threshold 10 [objects] send_timeout 600 [seconds] sess_timeout 5 [seconds] sess_workspace 16384 [bytes] session_linger 50 [ms] session_max 100000 [sessions] shm_reclen 255 [bytes] shm_workspace 8192 [bytes] shortlived 10.000000 [s] syslog_cli_traffic on [bool] thread_pool_add_delay 2 [milliseconds] thread_pool_add_threshold 2 [requests] thread_pool_fail_delay 200 [milliseconds] thread_pool_max 2000 [threads] thread_pool_min 5 [threads] thread_pool_purge_delay 1000 [milliseconds] thread_pool_stack unlimited [bytes] thread_pool_timeout 300 [seconds] thread_pool_workspace 65536 [bytes] thread_pools 2 [pools] thread_stats_rate 10 [requests] user varnish (106) vcc_err_unref on [bool] vcl_dir /etc/varnish vcl_trace off [bool] vmod_dir /usr/lib/varnish/vmods waiter default (epoll, poll) This is our default.vcl file: LINK sub vcl_recv { # BASIC recv COMMANDS: # # lookup -> search the item in the cache # pass -> always serve a fresh item (no-caching) # pipe -> like pass but ensures a direct-connection with the backend (no-cache AND no-proxy) # Allow the backend to serve up stale content if it is responding slow. # This defines when Varnish should use a stale object if it has one in the cache. set req.grace = 30s; if (client.ip == "127.0.0.1") { # request from NGINX - do not alter X-Forwarded-For set req.http.HTTPS = "on"; } else { # Add an X-Forwarded-For to keep track of original request unset req.http.HTTPS; unset req.http.X-Forwarded-For; set req.http.X-Forwarded-For = client.ip; } set req.backend = www_director; # Strip all cookies to force an anonymous request when the back-end servers are down. if (!req.backend.healthy) { unset req.http.Cookie; } ## HHTP Accept-Encoding if (req.http.Accept-Encoding) { if (req.http.Accept-Encoding ~ "gzip") { set req.http.Accept-Encoding = "gzip"; } else if (req.http.Accept-Encoding ~ "deflate") { set req.http.Accept-Encoding = "deflate"; } else { unset req.http.Accept-Encoding; } } if (req.request != "GET" && req.request != "HEAD" && req.request != "PUT" && req.request != "POST" && req.request != "TRACE" && req.request != "OPTIONS" && req.request != "DELETE") { /* non-RFC2616 or CONNECT */ return (pipe); } if (req.request != "GET" && req.request != "HEAD") { /* only deal with GET and HEAD by default */ return (pass); } if (req.http.Authorization) { return (pass); } if (req.http.HTTPS ~ "on") { return (pass); } ###################################################### # COOKIE HANDLING ###################################################### # METHOD 1: do not remove cookies, but pass the page if they contain TB_NC if (!(req.url ~ "(?i)\.(png|gif|ipeg|jpg|ico|swf|css|js)(\?[a-z0-9]+)?$")) { if (req.http.Cookie && req.http.Cookie ~ "TB_NC") { return (pass); } } return (lookup); } # Code determining what to do when serving items from the IIS Server sub vcl_fetch { unset beresp.http.Server; set beresp.http.Server = "Server-1"; # Allow items to be stale if needed. This is the maximum time Varnish should keep an object. set beresp.grace = 1h; if (req.url ~ "(?i)\.(png|gif|ipeg|jpg|ico|swf|css|js)(\?[a-z0-9]+)?$") { unset beresp.http.set-cookie; } # Default Varnish VCL logic if (!beresp.cacheable || beresp.ttl <= 0s || beresp.http.Set-Cookie || beresp.http.Vary == "*") { set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has specific TB_NC no-caching cookie if (req.http.Cookie && req.http.Cookie ~ "TB_NC") { set beresp.http.X-Cacheable = "NO:Got Cookie"; set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has Cache-Control private else if (beresp.http.Cache-Control ~ "private") { set beresp.http.X-Cacheable = "NO:Cache-Control=private"; set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has Cache-Control no-cache or Pragma no-cache else if (beresp.http.Cache-Control ~ "no-cache" || beresp.http.Pragma ~ "no-cache") { set beresp.http.X-Cacheable = "NO:Cache-Control=no-cache (or pragma no-cache)"; set beresp.ttl = 120 s; return(hit_for_pass); } # If we reach to this point, the object is cacheable. # Cacheable but with not enough ttl: we need to extend the lifetime of the object artificially # NOTE: Varnish default TTL is set in /etc/sysconfig/varnish # and can be checked using the following command: # varnishadm param.show default_ttl else if (beresp.ttl < 1s) { set beresp.ttl = 5s; set beresp.grace = 5s; set beresp.http.X-Cacheable = "YES:FORCED"; } # Cacheable and with valid TTL. else { set beresp.http.X-Cacheable = "YES"; } # DEBUG INFO (Cookies) # set beresp.http.X-Cookie-Debug = "Request cookie: " + req.http.Cookie; return(deliver); } sub vcl_error { set obj.http.Content-Type = "text/html; charset=utf-8"; if (obj.status == 404) { synthetic {" <!-- Markup for the 404 page goes here --> "}; } else if (obj.status == 500) { synthetic {" <!-- Markup for the 500 page goes here --> "}; } else if (obj.status == 503) { if (req.restarts < 4) { return(restart); } else { synthetic {" <!-- Markup for the 503 page goes here --> "}; } } else { synthetic {" <!-- Markup for a generic error page goes here --> "}; } } sub vcl_deliver { if (obj.hits > 0) { set resp.http.X-Cache = "HIT"; } else { set resp.http.X-Cache = "MISS"; } } Thanks in advance,

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• Performance of file operations on thousands of files on NTFS vs HFS, ext3, others

  - by peterjmag

  [Crossposted from my Ask HN post. Feel free to close it if the question's too broad for superuser.] This is something I've been curious about for years, but I've never found any good discussions on the topic. Of course, my Google-fu might just be failing me... I often deal with projects involving thousands of relatively small files. This means that I'm frequently performing operations on all of those files or a large subset of them—copying the project folder elsewhere, deleting a bunch of temporary files, etc. Of all the machines I've worked on over the years, I've noticed that NTFS handles these tasks consistently slower than HFS on a Mac or ext3/ext4 on a Linux box. However, as far as I can tell, the raw throughput isn't actually slower on NTFS (at least not significantly), but the delay between each individual file is just a tiny bit longer. That little delay really adds up for thousands of files. (Side note: From what I've read, this is one of the reasons git is such a pain on Windows, since it relies so heavily on the file system for its object database.) Granted, my evidence is merely anecdotal—I don't currently have any real performance numbers, but it's something that I'd love to test further (perhaps with a Mac dual-booting into Windows). Still, my geekiness insists that someone out there already has. Can anyone explain this, or perhaps point me in the right direction to research it further myself?

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• SAN performance issues storing SQL Server tempdb on a SAN that's being backed up

  - by user42724

  I'm afraid I don't know much about SAN's so please forgive my lack of detail or technical terms. As a developer I've just completed and put on an existing production system a new application but it would appear to have tipped the scales regarding the performance of the backups being taken from the SAN. As I understand it there's a mirror of the SAN being taken usually constantly at the block-level. However, there seem to be so many new writes to the disk that the SAN mirroring/backup process can no longer keep up. I believe I've narrowed this down to SQL Servers tempdb which exists on a drive that contributes the largest portion of the problem! In fact I think tempdb has be contributing the largest portion of the issues all along regardless of my application! My question therefore is whether the tempdb should ever be mirrored or backed on the SAN and whether anyone else has gone through this sort of pain already? I'm wondering whether it's a best practise to make sure that tempdb is never mirrored on a SAN simply because any writes to it don't need to be saved. This also raises a slightly connected question - is it better to rely on SQL Servers built-in database backups tools (DB in full-recovery mode with full/differential and transaction log backups) or, as is the case with our application, SQL server is in simple recovery mode and never backed up since the SAN is mirrored and backed up? Many thanks

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• Outbound HTTP performance tuning recommendations

  - by Richard Gadsden

  I'll detail my exact setup below, but general recommendations for a better web-browsing experience will be useful. A nice checklist of things to try would be great! I have 600 users on a single site with an 8MB leased line. I get a lot of moans about the performance of "the internet" (ie web-browsing). What recommendations do the community have for speeding things up without just throwing more bandwidth at it? I expect I will end up buying some more, but good management tips are always valuable. My setup is this: Cisco PIX (515E) firewall on the edge of the network. It's just doing some basic NAT, and opening up a handful of ports to various bastion hosts (aka DMZ servers). The DMZ is just a switch that the servers are plugged into. ISA 2006 Enterprise array (two servers) connecting DMZ to the internal LAN, with WebSense Web Security filtering HTTP traffic so users can't look at porn or waste bandwidth on YouTube during working hours. I've done a few things - I've just switched my internal DNS over to use root hints, which halved DNS query latency from 500ms to 250ms. Well worth doing. I'm trying to cache more aggressively, but so much more of the internet is AJAXy and doesn't cache very well as compared to five years ago. Plus the 70GB of cache which felt like a lot a few years ago really isn't any more. I'm getting about 45% cache hits by number of requests, but only about 22% by size, ie larger objects are less likely to be cached. Latency seems to be part of the problem. Is that attributable to the bandwidth problem, or are there things I can look at to try to reduce latency even on heavily-loaded bandwidth?

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• Strange performance differences in read/write from/to USB flash drive

  - by Mario De Schaepmeester

  When copying files from my 8GB USB 2.0 flash drive with Windows 7 to a traditional hard drive, the average speed is between 25 and 30 MB/s. When doing the reverse, copying to the USB drive, the speed is 5MB/s average. I have tested this with about 4.5GB of files, a mixture of smaller and larger ones. The observations were the same on both FAT32 and exFAT file systems on the USB drive, NTFS on the internal hard disk. I don't think I can be mistaken in saying that flash memory has a lot higher performance than a spinning hard drive in both terms of reading and writing. For both memory types, reading should be faster than writing too. Now I wonder, how can it be that copying files from a fast read memory to a faster write memory is actually slower than copying files from a fast read memory to a slow write memory? I think that the files are stored in RAM before being copied over too, and there's caching as well, but I don't see how even that could tip the balance. It can only be in the advantage of writing to the USB drive, since it is "closer" to the SATA system than the USB port and it will receive data from the internal SATA HDD faster. Perhaps my way of thinking is all wrong or it just depends on the manufacturer of the USB pen. But I am curious.

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• Poor gaming performance with hyper-v installed in windows 8

  - by SnowCrash

  I am getting very poor gaming performance on my Windows 8 host OS with Hyper-V installed but no guest machines running. For example World of Tanks reports 60-70 FPS without Hyper-V installed and 4-14 FPS with it installed. A similar, dramatic, hit is observed in several other games so the issue is not WoT specific. To make the point clear, I am not trying to run games in a virtual machine. I don't even have a VM running while observing this effect. I simply have the Hyper-V feature installed. My system specs: AMD Phenom II 965 (3.4 GHz) AMD Radeon 6950 2GB (XFX Double D HD-695X-CDFC) 16GB DDR3 1333 AMD 790GX chipset Mainboard (Gigabyte GA-MA790GPT-UD3H) I have tried every AMD driver from 12.8 to the current 12.11beta8, virtualization is enabled in the BIOS settings, the onboard 3300HD video device is disabled in BIOS and I have read the MSDN blog entry here regarding a similar issue in Server 2008 that was resolved in 2008 R2 (and hopefully not regressed in Win 8). I'd like to be able to use Hyper-V for development and testing at home (I am a sysadmin/software developer professionally). If, however, I can't also use my home system for entertainment I'll have to scrap those plans.

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• SSD, AHCI and write performance

  - by Dan

  We've started to deploy SSD drives to our developers workstations. At this moment we're having the unpleasant surprise that the systems using the new SSDs often freeze, with the HDD activity led blinking or being continuously on. Benchmarks shows read speeds around 180 MB/s, but write speeds around 5 MB/s. All developers are using Windows 7 Enterprise, 64 bit, SP1. One of our developers suggested (based on his experience) the following sequence: backup the workstation use a tool to completely erase the SSD make sure AHCI is enabled in BIOS install Windows restore from backup So far, this procedure seems to work (we're still testing, but write speed seems to be 120 MB/s). There are some questions in this context: why do we have to completely reinstall Windows? Is it possible to clean the SSD without reinstalling Windows? Is there a reliable tool? If AHCI was disabled when Windows was installed and we enable it, shouldn't this be enough to correct the write performance issue? If we have to completely erase the SSDs, does this mean the SSDs we've received were used before (SH)? I'm wondering this because the package I've got was open (I didn't think about it at that time, as I considered one of my coworkers simply took a peek inside the package). Has anyone seen a similar problem before?

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• Poor Write Performance in VM inside Proxmox PVE 2.0

  - by sorsenne

  I am running a PVE 2.0 on a decent Hardware (2 SATA HDDs as RAID1, 12GB RAM, i7 CPU) but the I/O Performance is very poor inside the VM (Ubuntu 11.10 Server). The very same VM was copied to another Server running simply Ubuntu Server with KVM and had better I/O Perf. this is how the HDD is shown in the Guest: ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) ata1.00: ATA-8: ST3000DM001-9YN166, CC49, max UDMA/133 ata1.00: 5860533168 sectors, multi 16: LBA48 NCQ (depth 31/32), AA ata1.00: configured for UDMA/133 scsi 0:0:0:0: Direct-Access ATA ST3000DM001-9YN1 CC49 PQ: 0 ANSI: 5 sd 0:0:0:0: [sda] 5860533168 512-byte logical blocks: (3.00 TB/2.72 TiB) sd 0:0:0:0: [sda] 4096-byte physical blocks sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA I tested with DD: $ dd bs=1M count=128 if=/dev/zero of=test conv=fdatasync 128+0 records in 128+0 records out 134217728 bytes (134 MB) copied, 19.2222 s, 7.0 MB/s on the Host, this same Test will result with 156 MB/s in average. PS: I am using VirtIO and see no error in dmesg.

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• Strange ASP.NET Queue Performance Counters Behavior?

  - by LemurTech

  We have an ASP.NET 2.0 site running in classic mode. I am seeing very strange behavior in the performance counter values. Perhaps these are bugs (I've been all over Google trying to verify this, without much luck), or perhaps it is just my inexperience with monitoring these things. This PerfMon graph (http://imgur.com/Jv5io5J) represents a load test where I add up to 350 virtual users to the site, at a rate of about 1/sec, performing relatively simple page browsing. At the end of the test, I gradually taper off the number of users. This is a 4 CPU server. Machine.config settings for are at the defaults. The solid blue line is ASP.NET Apps v2.x\Requests Executing for the application in question. The profile makes perfect sense, with a quick ramp-up to 32 executing requests (minWorkerThreads x 4CPUs), followed by a slower ramp-up to 48 ((maxWorkerThreads - minWorkerThreads) x 4CPUs). The solid yellow line is ASP.NET v2.x\Requests Queued. Again, this makes sense: after the initial 32 request threads are activated, the queue begins to build as new thread initialization can't keep pace with incoming requests. But as executing requests reaches its highest possible value of 48, the counter for ASP.NET Apps v2.x\Requests Queued (green solid line) suddenly springs to life and maintains step with the yellow counter. As far as I can tell, and with no other apps running on the server, these two counters should have had the same values from the start. One other odd thing: The counter for ASP.NET v2.x\Request Wait Time (dotted yellow line) also does not spring to life until executing requests reaches 48. Shouldn't I be seeing values here from the moment ASP.NET v2.x\Requests Queued begins to build? And likewise, why would ASP.NET Apps v2.x\Request Execution Time (dotted blue) increase significantly only after that peak of 48 is reached? Shouldn't it ramp-up gradually along with queued requests?

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• Very poor SCSI hd performance on IBM x336 with LSI 1030 RAID1

  - by David Tschoepe

  I'm experiencing very poor performance on an IBM x336 server with dual 73GB 15k hard drives on a U320 controller, LSI 1030. We're getting maybe 3.5MB/sec max (per HD Tune utility). It should be over 100MB/sec at least, I would think (another x335 box is running 70-80MB/sec). The server was recently setup and didn't really notice the problem, but may have been there from the beginning, so not sure. I have installed the IBM ServerRAID Windows utility. The server is running Windows 2008 R2 Web edition (if that matters). I thought maybe one of the drives was bad, so far I have removed one of the drives out of the array and tested again, but still the same results. I'm waiting for the RAID1 to resync and I will try pulling the other drive next. I've also used the ServerRAID utility but haven't noticed anything in there that might indicate a problem. Not sure if I'm on the right path here. So looking for some advice to track this down.

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• performance wise htaccess

  - by purpler

  hese's the my htaccess template, i wonder if anything could be added to increase website performance.. # Defaults AddDefaultCharset UTF-8 DefaultLanguage en-US ServerSignature Off FileETag None Header unset ETag Options -MultiViews #Options All -Indexes # Force the latest IE version or ChromeFrame <IfModule mod_setenvif.c> <IfModule mod_headers.c> BrowserMatch MSIE ie Header set X-UA-Compatible "IE=Edge,chrome=1" env=ie </IfModule> </IfModule> # Proxy X-UA Setup <IfModule mod_headers.c> Header append Vary User-Agent </IfModule> #Rewrites Options +FollowSymlinks RewriteEngine On RewriteBase / # Redirect to non-WWW RewriteCond %{HTTPS} !=on RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC] RewriteRule ^(.*)$ http://%1/$1 [R=301,L] # Redirect to WWW RewriteCond %{HTTP_HOST} ^domain.com RewriteRule (.*) http://www.domain.com/$1 [R=301,L] # Redirect index to root RewriteRule ^(.*)index\.(php|html)$ /$1 [R=301,L] # Caching ExpiresActive On ExpiresDefault A0 Header set Cache-Control "public" # 1 Year Long Cache <FilesMatch "\.(flv|fla|ico|pdf|avi|mov|ppt|doc|mp3|wmv|wav|png|jpg|jpeg|gif|swf|js|css|ttf|eot|woff|svg|svgz)$"> ExpiresDefault A31622400 </FilesMatch> # Proxy Caching <FilesMatch "\.(css|js|png)$"> ExpiresDefault A31622400 Header set Cache-Control "private" </FilesMatch> # Protect against DOS attacks by limiting file upload size LimitRequestBody 10240000 # Proper SVG serving AddType image/svg+xml svg svgz AddEncoding gzip svgz # GZip Compression <IfModule mod_deflate.c> <FilesMatch "\.(php|html|css|js|xml|txt|ttf|otf|eot|svg)$" > SetOutputFilter DEFLATE </FilesMatch> </IfModule> # Error page ErrorDocument 404 /404.html # Deny access to sensitive files <FilesMatch "\.(htaccess|ini|log|psd)$"> Order Allow,Deny Deny from all </FilesMatch>

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• Slow performance of MySQL database on one server and fast on another one, with similar configurations

  - by Alon_A

  We have a web application that run on two servers of GoDaddy. We experince slow preformance on our production server, although it has stronger hardware then the testing one, and it is dedicated. I'll start with the configurations. Testing: CentOS Linux 5.8, Linux 2.6.18-028stab101.1 on i686 Intel(R) Xeon(R) CPU L5609 @ 1.87GHz, 8 cores 60 GB total, 6.03 GB used Apache/2.2.3 (CentOS) MySQL 5.5.21-log PHP Version 5.3.15 Production: CentOS Linux 6.2, Linux 2.6.18-028stab101.1 on x86_64 Intel(R) Xeon(R) CPU L5410 @ 2.33GHz, 8 cores 120 GB total, 2.12 GB used Apache/2.2.15 (CentOS) MySQL 5.5.27-log - MySQL Community Server (GPL) by Remi PHP Version 5.3.15 We are running the same code on both servers. The Problem We have some function that executes ~30000 PDO-exec commands. On our testing server it takes about 1.5-2 minutes to complete and our production server it can take more then 15 minutes to complete. As you can see here, from qcachegrind: Researching the problem, we've checked the live graphs on phpMyAdmin and discovered that the MySQL server on our testing server was preforming at steady level of 1000 execution statements per 2 seconds, while the slow production MySQL server was only 250 executions statements per 2 seconds and not steady at all, jumping from 0 to 250 every seconds. You can clearly see it in the graphs: Testing server: Production server: You can see here the comparison between both of the configuration of the MySQL servers.Left is the fast testing and right is the slow production. The differences are highlighted, but I cant find anything that can cause such a behavior difference, as the configs are mostly the same. Maybe you can see something that I cant see. Note that our tables are all InnoDB, so the MyISAM difference is (probably) not relevant. Maybe it is the MySQL Community Server (GPL) that is installed on the production server that can cause the slow performance? Or maybe it needs to be configured differently for 64bit ? I'm currently out of ideas...

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• Disk usage on IIS, PHP5, performance problems.

  - by Jacob84

  Hi everybody, I'm quite worried with a performance problem that I'm facing in one of our production servers. I'm working for a hosting company, so you can imagine how heterogeneous the applications runnning here are. All started with a call of a client complaining about the speed loading a Joomla. The setup is IIS6 (Windows 2003) with PHP5 and FAST CGI wich normally works pretty well. I've tested the loading time and indeed, he was right. 7 or 8 seconds to load, when usually this can be accomplished in 2. Seeing this results, I started to check first CPU and RAM. Everithing normal, 2GB of RAM free, 3%-8% of CPU activity. That's what I call a relaxed server ;). Unfortunately, digging a little deeper I've found the 'PhysicalDisk' counters quite high (above 10), specially the read queues. I've used Process Explorer to see wich of those processes has the higher deltas, but everything seemed normal. As the problem is specially related to PHP pages, I've checked specific IIS counters, as Actual connections, Number of CGI requeriments and Number of ISAPI requeriments. CGI -> 3 to 7 ISAPI -> 5 to 9 Connections-> 90 to 120 (wich appears at the top of the graph) More than a solution (I know this is hard to find), I would like to know if you have an specifical methodology to face this kind of problems. Thanks a lot, as always.

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• Photoshop CS5 performance over network drive (cifs)

  - by grub

  Hello Everyone I did install a QNAP NAS TS410 for a customer (professional photographer) with 3 Hitachi Deskstar 7200rpm 2TB disk configured as RAID5. The NAS and the workstations are connected over a Gigabit network. He and his co-worker are accessing the photos (about 1TB of photos) over a mapped network drive from their windows machines (Windows XP - 32bit and Windows 7 Ultimate - 32bit). Both are using Photoshop CS5 to edit the photos. The problem is that to save a edited photo takes a really long time, it takes about 3 times as long to save a photo as to open it. After some tests I can exclude the network, the NAS and the windows machines as source of the issue. I think the problem is the Photoshop software and its handling of the network drives. Officially network drives are not supported by Adobe. I do not have any experience with the Adobe products, especially with Adobe Photoshop CS5. What are your recommendation to solve the performance issue? Should my customer copy the photos to the local drive, edit them and upload them again to the network drive or is Adobe Drive or Adobe Version Cue the answer? One requirement is that the photos need to be accessible / editable from both computers even when one of them is offline. Adobe Version Cue needs a dedicated service running to be usable, so this solution is not possible as far as I understand the Cue software. Thank you for your input to this issue and have a nice day :-) Greetings grub

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• Performance decrease in every game and application

  - by Márk Vincze

  When I start a game, initially it runs smoothly, but after a couple of minutes, the performance gradually decreases to the point of being unplayable (1-2 FPS). The sound also starts to lag at this point. This does not happen every time I start my PC, usually exiting the game, rebooting, then starting the game again solves the problem, and I can play with perfect FPS for as long as I want. I could not find any deterministic reason when this happens and when doesn't. It happens in every game I tried (SWTOR, Diablo 3, Skyrim), and not even games, but simple applications like a browser or the Control Panel can get unusably slow. This is a brand new PC I bought three months ago, and this problem occurs since the first day I've been using it. Could you provide any advice how to further diagnose the problem? I tried to reinstall Windows, and tried different video card drivers, but it did not help. It would be important to know whether this is a hardware or software problem, because I can use the warranty if it is a hardware issue. (I did not want to return the PC yet, because I can't reproduce the issue deterministically.) Spec of the pc: Motherboard: ASROCK H61M-HVS CPU: INTEL Core i3-2120 3.30GHz 1155 BOX Memory: KINGMAX 4096MB DDR3 1333MHz KIT Video card: GIGABYTE GV-R685OC-1GD HD6850 1GB GDDR5 PCIE HDD: SEAGATE 500GB Barracuda 7200rpm 16MB SATA3 ST500DM002 I am using Windows 7 64 bit. Thanks a lot in advance!

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• file read performance degrades as number of files increases

  - by bfallik-bamboom

  We're observing poor file read IO results that we'd like to better understand. We can use fio to write 100 files with a sustained aggregate throughput of ~700MB/s. When we switch the test to read instead of write, the aggregate throughput is only ~55MB/s. The drop seems related to the number of files since the throughput for read and write are comparable for a single file then diverge proportionally as we increase the number of files. The test server has 24 CPU cores, 48GB of memory, and is running CentOS 6.0. The disk hardware is a RAID 6 array with 12 disks and a Dell H800 controller. This device is partitioned with ext4 using the default settings. Increasing the readahead (using blockdev) improves the read throughput significantly but it still doesn't match write speed. For instance, increasing the readahead from 128KB to 1M improved the read throughput to ~145MB/s. Is this a known performance issue in our OS/disk/filesystem configuration? If so, how can we tell? If not, what tools or tests can we use to further isolate the issue? Thanks.

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• How can I most accurately calculate the execution time of an ASP.NET page while also displaying it o

  - by henningst

  I want to calculate the execution time of my ASP.NET pages and display it on the page. Currently I'm calculating the execution time using a System.Diagnostics.Stopwatch and then store the value in a log database. The stopwatch is started in OnInit and stopped in OnPreRenderComplete. This seems to be working quite fine, and it's giving a similar execution time as the one shown in the page trace. The problem now is that I'm not able to display the execution time on the page because the stopwatch is stopped too late in the life cycle. What is the best way to do this?

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• SQL SERVER – 3 Online SQL Courses at Pluralsight and Free Learning Resources

  - by pinaldave

  Usain Bolt is an inspiration for all. He broke his own record multiple times because he wanted to do better! Read more about him on wikipedia. He is great and indeed fastest man on the planet. Usain Bolt – World’s Fastest Man “Can you teach me SQL Server Performance Tuning?” This is one of the most popular questions which I receive all the time. The answer is YES. I would love to do performance tuning training for anyone, anywhere.  It is my favorite thing to do, and it is my favorite thing to train others in.  If possible, I would love to do training 24 hours a day, 7 days a week, 365 days a year.  To me, it doesn’t feel like a job. Of course, as much as I would love to do performance tuning 24/7/365, obviously I am just one human being and can only be in one place t one time.  It is also very difficult to train more than one person at a time, and it is difficult to train two or more people at a time, especially when the two people are at different levels.  I am also limited by geography.  I live in India, and adjust to my own time zone.  Trying to teach a live course from India to someone whose time zone is 12 or more hours off of mine is very difficult.  If I am trying to teach at 2 am, I am sure I am not at my best! There was only one solution to scale – Online Trainings. I have built 3 different courses on SQL Server Performance Tuning with Pluralsight. Now I have no problem – I am 100% scalable and available 24/7 and 365. You can make me say the same things again and again till you find it right. I am in your mobile, PC as well as on XBOX. This is why I am such a big fan of online courses.  I have recorded many performance tuning classes and you can easily access them online, at your own time.  And don’t think that just because these aren’t live classes you won’t be able to get any feedback from me.  I encourage all my viewers to go ahead and ask me questions by e-mail, Twitter, Facebook, or whatever way you can get a hold of me. Here are details of three of my courses with Pluralsight. I suggest you go over the description of the course. As an author of the course, I have few FREE codes for watching the free courses. Please leave a comment with your valid email address, I will send a few of them to random winners. SQL Server Performance: Introduction to Query Tuning  SQL Server performance tuning is an art to master – for developers and DBAs alike. This course takes a systematic approach to planning, analyzing, debugging and troubleshooting common query-related performance problems. This includes an introduction to understanding execution plans inside SQL Server. In this almost four hour course we cover following important concepts. Introduction 10:22 Execution Plan Basics 45:59 Essential Indexing Techniques 20:19 Query Design for Performance 50:16 Performance Tuning Tools 01:15:14 Tips and Tricks 25:53 Checklist: Performance Tuning 07:13 The duration of each module is mentioned besides the name of the module. SQL Server Performance: Indexing Basics This course teaches you how to master the art of performance tuning SQL Server by better understanding indexes. In this almost two hour course we cover following important concepts. Introduction 02:03 Fundamentals of Indexing 22:21 Practical Indexing Implementation Techniques 37:25 Index Maintenance 16:33 Introduction to ColumnstoreIndex 08:06 Indexing Practical Performance Tips and Tricks 24:56 Checklist : Index and Performance 07:29 The duration of each module is mentioned besides the name of the module. SQL Server Questions and Answers This course is designed to help you better understand how to use SQL Server effectively. The course presents many of the common misconceptions about SQL Server, and then carefully debunks those misconceptions with clear explanations and short but compelling demos, showing you how SQL Server really works. In this almost 2 hours and 15 minutes course we cover following important concepts. Introduction 00:54 Retrieving IDENTITY value using @@IDENTITY 08:38 Concepts Related to Identity Values 04:15 Difference between WHERE and HAVING 05:52 Order in WHERE clause 07:29 Concepts Around Temporary Tables and Table Variables 09:03 Are stored procedures pre-compiled? 05:09 UNIQUE INDEX and NULLs problem 06:40 DELETE VS TRUNCATE 06:07 Locks and Duration of Transactions 15:11 Nested Transaction and Rollback 09:16 Understanding Date/Time Datatypes 07:40 Differences between VARCHAR and NVARCHAR datatypes 06:38 Precedence of DENY and GRANT security permissions 05:29 Identify Blocking Process 06:37 NULLS usage with Dynamic SQL 08:03 Appendix Tips and Tricks with Tools 20:44 The duration of each module is mentioned besides the name of the module. SQL in Sixty Seconds You will have to login and to get subscribed to the courses to view them. Here are my free video learning resources SQL in Sixty Seconds. These are 60 second video which I have built on various subjects related to SQL Server. Do let me know what you think about them? Here are three of my latest videos: Identify Most Resource Intensive Queries – SQL in Sixty Seconds #028 Copy Column Headers from Resultset – SQL in Sixty Seconds #027 Effect of Collation on Resultset – SQL in Sixty Seconds #026 You can watch and learn at your own pace.  Then you can easily ask me any questions you have.  E-mail is easiest, but for really tough questions I’m willing to talk on Skype, Gtalk, or even Facebook chat.  Please do watch and then talk with me, I am always available on the internet! Here is the video of the world’s fastest man.Usain St. Leo Bolt inspires us that we all do better than best. We can go the next level of our own record. We all can improve if we have a will and dedication.  Watch the video from 5:00 mark. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Training, SQLServer, T SQL, Technology, Video

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