WebSVN RSS feed – SmartDukaanThu, 01 Oct 2026 15:33:50 +0530WebSVN 2.8.6-DEVenhttps://svn.smartdukaan.com/log.php?repname=SmartDukaan&path=%2Ftrunk%2Fprofitmandi-common%2Fsrc%2Fmain%2Fjava%2Fcom%2Fspice%2Fprofitmandi%2Fcommon%2Futil%2FBrowserLane.java&max=40& Thu, 17 Sep 2026 13:12:56 +0530amit<div><strong>amit – 1 file(s) modified</strong><br/>Add BrowserLane: machine-wide interlock so only one headless Chrome runs at a time<br /> <br /> Every ChromeDriver tree on the app box costs ~850MB RSS, on a host holding a<br /> -Xmx8g tomcat and a -Xmx2g cron jar on 16GB that has been kernel-OOM-killed<br /> twice with tomcat the victim. Peak concurrent drivers is the number that<br /> matters, not drivers per day.<br /> <br /> Measured on the oppo/realme lane: a 25-imei chunk takes 505s (12s driver<br /> startup, then ~19.7s an imei) against a fixed 20s fixedDelay, i.e. a 96% duty<br /> cycle. Meanwhile tomcat starts its own driver 8 times a day for the knowlarity<br /> scrape. On 17-Sep that scrape ran 11:40:00-11:41:07 and the lane's next driver<br /> came up at 11:42:21 -- it cleared by 74 seconds, by luck. At a 96% duty cycle<br /> the collision cannot be dodged by choosing better times, only by serialising.<br /> <br /> The two JVMs are separate processes owned by different users, so an in-process<br /> flag cannot see across the boundary. Uses an OS file lock at<br /> /var/lock/sd-browser.lock (overridable via -Dsd.browser.lock), created 0666 on<br /> first use because cron runs as root and tomcat as tomcat and whichever starts<br /> first creates it. A file lock rather than a marker file so the kernel reclaims<br /> it when the holder dies: verified by SIGKILLing the holder mid-hold, the next<br /> JVM acquired in 264ms. A ReentrantLock gates it first, since a second thread in<br /> the same JVM would otherwise get OverlappingFileLockException rather than block.<br /> <br /> Callers wait rather than skip. The knowlarity scrape needs 67s against a lane<br /> busy 96% of the time, so skip-on-contention would mean it essentially never<br /> refreshed again. Eight scrapes a day costs the imei lane about nine minutes of<br /> waiting in total.<br /> <br /> Fails open if the lock file is unusable (missing /var/lock, read-only mount, dev<br /> laptop): serialising within the JVM only, rather than stopping imei activation<br /> over what is a safety interlock.</div>+ /trunk/profitmandi-common/src/main/java/com/spice/profitmandi/common/util/BrowserLane.java<br />https://svn.smartdukaan.com/revision.php?repname=SmartDukaan&path=%2Ftrunk%2Fprofitmandi-common%2Fsrc%2Fmain%2Fjava%2Fcom%2Fspice%2Fprofitmandi%2Fcommon%2Futil%2FBrowserLane.java&rev=37672https://svn.smartdukaan.com/revision.php?repname=SmartDukaan&path=%2Ftrunk%2Fprofitmandi-common%2Fsrc%2Fmain%2Fjava%2Fcom%2Fspice%2Fprofitmandi%2Fcommon%2Futil%2FBrowserLane.java&rev=37672