add more download and trace information

README.md

@@ -1,11 +1,12 @@
 ## Anonymized Cache Request Traces from Twitter Production
 
 ### Trace Overview
-This repository describes the traces from Twitter's in-memory caching ([Twemcache](https://github.com/twitter/twemcache)/[Pelikan](https://github.com/twitter/pelikan)) clusters. The current traces were collected from one instance of 54 clusters in Mar 2020. The traces are one-week-long. 
+This repository describes the traces from Twitter's in-memory caching ([Twemcache](https://github.com/twitter/twemcache)/[Pelikan](https://github.com/twitter/pelikan)) clusters. The current traces were collected from 54 clusters in Mar 2020. The traces are one-week-long. 
 More details are described in the following paper and blog. 
 * [Juncheng Yang, Yao Yue, Rashmi Vinayak, A large scale analysis of hundreds of in-memory cache clusters at Twitter. _14th USENIX Symposium on Operating Systems Design and Implementation (OSDI 20)_, 2020](https://www.usenix.org/conference/osdi20/presentation/yang). 
 * blog post 
 
+---
 
 ### Trace Format 
 The traces are compressed with [zstd](https://github.com/facebook/zstd), to decompress run `zstd -d /path/file`. 
@@ -26,43 +27,64 @@ Note that during key anonymization, we preserve the namespaces, for example, if
 A sample of the traces are attached under samples. 
 
 
+---
+
 ### Trace Download 
-The full traces are large (3.2 TB in compressed form, 14 TB uncompressed), and can be downloaded from the following places. 
+The full traces are large (2.8 TB in compressed form, 14 TB uncompressed), and can be downloaded from the following places. 
+
+#### Carnegie Mellon University PDL cluster
+https://ftp.pdl.cmu.edu/pub/datasets/twemcacheWorkload/open_source
+
+#### SNIA 
+
+#### Storj 
+see [storj](storj) for how to access (Good for worldwide access, especially Asia and Europe, but not available after Dec 2020)
+
+#### Baidu pan
+https://pan.baidu.com/s/1Jm2nAW-UhsjXU6JYoA07LA access code: wcws (Good for Asia access, but UI only has Chinese)
+
 
-  * Carnegie Mellon University PDL lab cluster: https://ftp.pdl.cmu.edu/pub/datasets/twemcacheWorkload/open_source
-  * SNIA 
-  * Storj 
-  * Baidu pan 
+These traces are splitted into smaller files of 1000000000 lines (smaller for SNIA) each and compressed with zstd, so a file with name clusterN.0.zst means this file contains the first 1000000000 requests of cluster N. 
 
-These traces are splitted into smaller files of 1000000000 lines (100000000 for SNIA) each and compressed with zstd, so a file with name X_cache.0.zst means this file contains the first 1000000000 requests of X_cache cluster trace. 
+Feel free to contact us if you have problem downloading the traces. 
+
+
+---
 
 ### Choice of traces for different evaluations 
-miss ratio related (admission, eviction)
+For different evaluation purposes, we recommend the following clusters/workloads 
+
+* **miss ratio related (admission, eviction)**: cluster52, cluster17 (low miss ratio), cluster18 (low miss ratio), cluster24, cluster44, cluster45, cluster29. 
 
-write-heavy workloads 
 
+* **write-heavy workloads**: cluster12, cluster15, cluster31, cluster37. 
 
-TTL-related 
-  mix of small and large TTLs 
 
+* **TTL-related**: mix of small and large TTLs: cluster 52, cluster22, cluster25, cluster11; small TTLs only: cluster18, cluster19, cluster6, cluster7. 
 
-  small TTLs only 
 
+---
 
-Object sizes 
-  Small objects 
 
+### More information about each workload is included under `stat/`
+We release a computed statistics of each cluster workload under `stat/`, the latest is [here](stat/2020Mar.md). 
+This table includes the following fields, each field is the mean value of the metric either from production or from the traces. 
 
-  Large objects 
+The fields include `production miss ratio`, 
+`workload category` (1: storage, 2: computation, 3: transient item), `key size`, `value size`, `request rate`, `mean object frequency`, `one-hit-wonder ratio (%)`, `compulsory miss ratio (%)`, `common TTLs`, `working set size`, `operations`, `Zipf alpha`. 
 
 
+---
+
 ### Misc 
   * Please join our [discussion channel](http://groups.google.com/group/?) for questions and updates. 
   * We provide a **[trace bibliography](bibliography.bib)** of papers that have used and/or analyzed the traces, and encourage anybody who publishes one to add it to the bibliography by creating an issue or pull request on GitHub. 
 
 
+---
+
 ### Acknowledgement 
-  We thank SNIA and Carnegie Mellon University PDL lab for hosting the traces. 
+  We thank Carnegie Mellon University PDL lab, SNIA and Storj for hosting the traces. 
 
 
 ### License