[opencms-dev] I have modify some caching

[Kosol Tuanveeradej]

Dear all

I have some performace test and some modify code in method 
readFileHeader in org/opencms/db/generic/CmsVfsDriver.java to tell you 
all . If it make advantage or disavantage please suggest me.

Testing Environment
- oracle8.16   p3  1.6 GHz. Ram 512 Mb.
- IIS webserve jk2 rediract to tomcat5 and Opencms6 a2 on p4  2.0 GHz 
Ram 512 Mb.

First test.
opencms no static export no caching.
I use concurrent user 300 send request pages to webserver.
- Average response time about 70- more 100 secs perpage

Second test.
I have export all website to static on webserver.
I use concurrent user 300 send request to webserver.
- Average response time about 0.2 secs perpage (Verry good).

Third test
I have modify some code in org/opencms/db/generic/CmsVfsDriver.java, 
method  readFileHeader.
I have to do this because on production architecture I have two 
webservers running under loadbalancer,  on webserver i remove login 
module from opencms, and have a application server for edit contents at 
backend.
Other problem.
- exporting website use alot of time (lage website).
- when exporting web DB process will peak to 100% customer cannot access 
DB on that time (have another program use DB too).
- I cannot export all website as i wish and server reside in customer's 
datacenter, that i cannot walk in easily (sync two webservers by copy 
static export).

-Thanks for Caching code form http://www.vipan.com/htdocs/cachehelp.html 
(Vipan Singla) for testing, Thanks you.

Tesing result
- Average response time about 7 secs perpage at 500 concurrent users 
(good enough compare with first test).


Then i send the modified code for yous all comments!!
and Thank you advance for your comment!
My english may not good.

Kosol Tuanveeradej

/**
     * @see 
org.opencms.db.I_CmsVfsDriver#readFileHeader(I_CmsRuntimeInfo, int, 
java.lang.String, boolean)
     */
    public CmsFile readFileHeader(I_CmsRuntimeInfo runtimeInfo, int 
projectId, String path, boolean includeDeleted) throws CmsException {

        CmsFile fileHead = null;
        ResultSet res = null;
        PreparedStatement stmt = null;
        Connection conn = null;
        String fileHead_Key = null;
       
        /** tar add caching for this readFileHeader by
         * check if file exist in fileCache get file from cache
         * else read from database and put it into fileCache.
         * return file
         * read form database is original part of this readFileHeader.
         */
        fileHead_Key = path +" [fileHead]";
       
        if(projectId == 1){
            fileHead = (CmsFile)cache.get(fileHead_Key);
        }
             
        if(fileHead == null){
            // must remove trailing slash
            path = removeTrailingSeparator(path);
                   
            try {
                conn = m_sqlManager.getConnection(runtimeInfo);
                stmt = m_sqlManager.getPreparedStatement(conn, 
projectId, "C_RESOURCES_READ");
                stmt.setString(1, path);

                res = stmt.executeQuery();
                if (res.next()) {
                    fileHead = createFile(res, projectId, false);
                    while (res.next()) {
                        // do nothing only move through all rows because 
of mssql odbc driver
                    }

                    // check if this resource is marked as deleted
                    if ((fileHead.getState() == 
I_CmsConstants.C_STATE_DELETED) && !includeDeleted) {
                        throw new CmsException("[" + 
this.getClass().getName() + ".readFileHeader/3] " + fileHead.getName(), 
CmsException.C_RESOURCE_DELETED);
                    }
                } else {
                    throw new CmsVfsResourceNotFoundException("[" + 
this.getClass().getName() + ".readFileHeader/3] " + path);
                }
            } catch (SQLException e) {
                throw m_sqlManager.getCmsException(this, null, 
CmsException.C_SQL_ERROR, e, false);
            } catch (CmsException ex) {
                throw ex;
            } catch (Exception exc) {
                throw m_sqlManager.getCmsException(this, null, 
CmsException.C_UNKNOWN_EXCEPTION, exc, false);
            } finally {
                m_sqlManager.closeAll(runtimeInfo, conn, stmt, res);
            }
           
            // file never exist in fileCache then put it in fileCache. :tar
            if (projectId == 1){
                cache.admit(fileHead_Key,fileHead);
            }
   
       }

        return fileHead;
    }