Danhua Shao's Email Addresses & Phone Numbers

📖 Summary

Member Of Technical Staff @ Rubrik, Inc. Design and implement C++ library to improve performance of fileset backup and restore Designed and implemented a new plugin to speedup filesystem metadata scan via NFS protocol. Porting the backup agent (C++) from Linux to Solaris. San Francisco Bay AreaSenior Software Engineer @ Oracle Enhanced kernel modules and userland utilities for Solaris NFS (Network File System) v3/v4 client and server• Designed and implemented a new resource (open owner) allocation policy for Solaris NFS v4 client to enable parallel file open operation with same credential. • Designed and implemented Central Grace Manager which coordinates NFSv4 NLM, and SMB protocols to recovery locks on the same share during service restart/system reboot.• Designed and implemented pseudo device driver to notify NFS of storage pools and network interfaces update during ZFSSA cluster takeover/failback• Designed and implemented a library to provide NFS related services with programmable API • Enhanced performance of PRC on connection management and Duplicate Request Cache. United StatesSoftware Engineer @ Yahoo! Developed plugins for a scalable multi-thread and/or multi-process HTTP compliant proxy-caching server• Designed and implemented plugins within a cooperative user-level thread (fiber) framework to redirectHTTP requests and/or rewrite headers• Performance tests showed no performance degradation on servers with these pluginsEnhanced a data migration tool to migrate large scale critical data to data center with REST API• Investigated reasons for program crashing with memory profiling tools• Reduced memory consumption so that migration processes no longer crash while running in parallel• Utilized persistent connection to increase data migration rate• Cooperated with service engineers and customers while deploying new releases• All data (18 billion files, totally 4.5 Petabytes) have been migrated and verified ahead of deadlineDeveloped a cleanup tool to evict expired records in a large memory-mapped hash table• Minimized performance impact by throttling CPU and disk I/O usage• Provided API to support plugins which enable customized records query• Endurance tests showed no performance degradation on processes accessing the hash table simultaneouslyWorking as backend engineer to display Yahoo! Updates commenting together with the Facebook News Feed and Twitter. From July 2010 to June 2012 (2 years) Graduate Intern @ Sun Microsystems Inc Network File System group, May 2008 ­ Dec. 2008 Instrument DTrace probes into Solaris kernel to trace activities of NFS (Network File System) client and server. · Designed and implemented DTrace provider and probes to trace NFS v4.1 operations of meta-data server · Designed and implemented DTrace provider and probes to trace NFS v3 operations of client module. · Analyze performance of NFS client and server by tracing interactions between file system operations, NFS operations and network communications · DTrace probes for NFS v3 have been integrated into OpenSolaris. From May 2008 to December 2008 (8 months) Software Engineer Intern @ VMWare Inc Platform API group, Jun. 2007 ­ Aug. 2007Developed network configuration modules for ESX Server, a microkernel operating system (hypervisor) that supports multiple · Designed and implemented C++ interface to config DNS and virtual switch network module · Designed and implemented unit tests for the network configuration modules From June 2007 to August 2007 (3 months) Senior Software Engineer/Architect @ Beijing ChinaTech International Software Co., Ltd Commercialized A2E-MQ, a message-oriented middleware, to support reliable data transfer in distributed systems: · Designed a C/C++ library to support cross-platform programming on process/thread, file system, and network communication. · Designed and implemented a multi-threaded task scheduler to handle multiple service requests concurrently. · Designed a log-based rollback recovery protocol on file system to support reliable message storage. · A2E-MQ has been successfully used in the data report system of a major China petroleum companies, Sinopec (NYSE: SNP). From September 2001 to July 2004 (2 years 11 months)